Weldanpower 225 woes

[bmyers]

Got a weldanpower 225 awhile back and had to repair the oil/sump pan, which was cracked. I got the machine back together and have a problem or two:

1. The small wire that bolts to the engine on the back of the machine is causing some trouble. I believe this to be the kill wire. When it is unhooked, the machine seems to run fine..


2. The machine will not generate or weld at this time. I suspect these problems are related, but I am not for sure. I need to find a repair manual of some kind. I took the start/kill switch off and unhooked what would be the top right wire, looking from the back. The machine runs and seems to be idling right when I do this, whether or not the wire on the back is attached.


I do not have any way of knowing what wires are what, or what they should be carrying.

Any help would be greatly appreciated.

Thanks

[GBM]

I am new here and new to my Weldanpower 225 ...
but I suspect those are two different problems...
the kill wire is just to turn off the engine..
you have another problem if , when running, it will not produce electricity..
if you search on this site I think someone has posted an electrical schematic for this machine...
But a quick trip to your local Lincoln dealer might solve the problem fast and cheap..
or perhaps you can email pics of the inside of your machine to them...

[prop-doctor]

have you checked lincoln electrics site for maunal
www.lincolnelectric.com search the service navagator
use your code model number

[roadkillbobb]

wheres DUANE....he should be called Mr,Lincoln..LOL.. he will appear soon and answer all your questions...

[roadkillbobb]

in the meantime if you goto the lincoln websight you can down load all the manuals you need, sorry I dont have the link at my fingertips

[duaneb55]

Here's the link http://www.lincolnelectric.com/en-us/support/Pages/operator-manuals.aspx bobb was talking about and we'll need to know the unit code # and engine make in order to know which 225 you're dealing with.

[bmyers]

i will get the code asap. It is the Briggs 16 HP version.

[bmyers]

The code is 9444

Model WP225G7

So i got it to generate for a bit tonight. It is acting very funky, which is why I am struggling to nail down the problem.

Wire #203 that attaches to ground on the engine at the back is the one that I was having to disconnect to get a spark. When I did that, It would run, but I had no output.

Today I had everything hooked up, and it started, ran, and generated fine. I shut it off to get a volt meter and came back. It started right up and ran fine, but is not making power now.

I did have the engine off, but got it all back together right, or at least how it was before.

It seems maybe I have 2 problems here. The larger concern for me is the generating/welding part.

Where should I start testing to see what the problem possibly is? It seems it may be fairly simple, but I am not sure where to check first. I have the wiring diagram and manual from Lincoln, but simply do not know where to start!

[ccawgc]

Wire 203 is the start /run / stop wire for the engine. Open engine runs. Connected to ground engine stops. Wire 203 connects to wire 5 in the start/ run / stop switch in the stop position.
Wire 203 also connects to wire 220 through the switch. 220 goes to the oil pressure switch.
Must have oil pressure for engine to stay running. This switch also supplies 12vdc to the pc board. No 12vdc to pcb no output. The switch is 3 , 3 position switches ganged together.
Check the run and oil pressure switches out, one or both may be bad. I hope you have enough oil in the engine so there is oil pressure.

[bmyers]

Yes the engine is correct on oil. The run switch is the start/run/stop switch I assume? And for the oil switch, will it simply ground out if it is bad? If that is the case, I would think it wouldn't run at all.

Thanks a lot ccawgc for the help!

[duaneb55]

Yes, the RUN switch is the RUN/START/STOP switch and I would check it for possibly being bad as well as ccawgc suggested.

If the OPS is bad (not opening with oil pressure) you would need to disconnect it not ground it. With no oil pressure the switch closes to connect to ground and shorts the engine ignition thru the RUN/START/STOP switch.

Also check the plug at PC1 for corroded terminals and pins which could be the cause of the intermittent weld/generator output.

[bmyers]

Had a chance to do some more checking on the welder. so far I've found:

Wire 212A goes to the idler/high idle switch

Wire 212 goes to the board

wire 209A has 12V (not sure from where yet)

Wire 211 goes to the board

wire 211A goes back to the starter solenoid

wire 5G goes to ground??

wire 203 goes to ground at the back of the machine

wire 203A jumps from a post on the switch to 203.


I also tested the switch and can post a scan up of what I sketched out. I tested the switch for continuity between all 7 of the spades in all switch positions and cannot seem to understand what circuit it closes when you switch it to STOP.


Based on my testing of the switch I found that when the switch was in the RUN position:

-212 and 209A are closed together

-203A and 220 are closed together

In STOP position:

-5G and 203 are closed together

( this is what I don't quite understand)

In START position:

212 and 209 are closed together.

By closed together I mean had continuity.

I blew the diagram up and will check to verify they are at least all right, or as they are on the schematic. Any advice on checking the RUN switch? The oil pressure sensor switch is working.

thanks!

[duaneb55]

209 gets 12vdc(+) thru the ammeter from the battery side of the starter solenoid.

In STOP position, 5G connects to 203 to ground (short) the engine ignition mag to stop the engine.

You should also find that 211/211A and 5G connect in START position. If so, the STOP/RUN/START switch checks out.

[ccawgc]

All # 5 wires are connected together. They are your battery minus and ground system.
The different letters show they are different wire segments.
On engines with magnetic ignition systems. A magnet passes a coil causing a pulse of electricity and making the spark. as long as the magnet keeps going by the coil it keeps working. Engine runs until it runs out of gas. To stop the engine when we want to. we take a coil wire and short it to ground and this kills the spark and stops the engine.
This explains the closed switch in the stop position.
The coil on your car is a step up transformer that needs 12vdc turned on and off to make spark.
One more thought. Make sure you do not have to much oil in the engine. This also causes problems.

[duaneb55]

So bmyers, is this thing generating/welding again? I trust the engine starting/running/stopping issues are behind you. ??

[bmyers]

Hey Duane! Sorry for the delay I have been out of town and extremely busy. Had to get a few parts, and went ahead and put a carb kit on while I was at it. Got all the connections cleaned and everything put back together and it seems to be running great, but no power still.

Not sure where to go next on this. The start/stop switch checked out OK, but still no power, which would indicate that is/was not the problem.

Another small issue is I can not get it to idle down low enough. The mag is working, but it seems like it just won't pull back quite far enough. The idle screw is not the problem, as I backed it out plenty far. I have not messed with the spring system underneath, but I am afraid it may need adjustment- unless it is possible that the mag can get weak on these?

Thanks for all the help!!!

[bmyers]

Ok I looked at the troubleshooting guide from lincoln and discovered a few things:

1. The slip rings measured 4.4 Ohms all the way around- good according to the manual.

2. Rheostat checked out ok. (1-10 Ohms)

3. I disconnected lead #4 and D2 (diode) and lead #5B. Tested continuity between the 2- came out ok.

The auto idle is in fact working, so I do not believe it is the board. No loose wires or connections that I can see anywhere.

Other things on the troubleshooting list include lead #5 from the "field rectifier". I am not sure where this is and cannot find it on the diagram. I found the field capacitor on the diagram. Any other ideas on why this thing wouldnt be welding/generating?

[duaneb55]

Continuity between leads #4 and #5B confirms the field exciter output stator windings are OK. I don't have the specific voltage figure for this unit but when the generator is producing output, AC voltage on leads #4 and #5B is probably something in the neighborhood of 40-60 volts.

The "field rectifier" is that diode D2 that leads #4 and #5B attach to and is actually a full wave bridge rectifier that rectifies AC voltage to DC for the field exciter circuit to use after initial field flashing (excitation) from battery voltage.

The fact the AUTO IDLE is working only shows that portion of control board PCB1 is functioning. PCB1 performs several duties including initial field flashing to get things started which may be the root problem. An open flashing diode on PCB1 could be the cause and you can by-pass the board to test for generator/weld output by manually flashing the field at the brushes.

To do so, simply momentarily (a couple seconds) apply 12VDC to the rotor brushes circuits. There are several places you can do this to make it as easy as possible and you must apply the (+) and (-) to the correct wires such as:
12VDC(+)
1) wire #218 at the positive brush holder
2) wire #218 at the Fine Current Control rheostat
3) wire #200 at field rectifier D2
4) wire #200 at the Fine Current Control rheostat
5) wire #200A at the field capacitor
(For 3-5, Fine Current control should be set to Maximum)

12VDC(-)
1) wire #201 at the negative (-) brush holder
2) wire #201/201A at field rectifier D2
3) wire #201B at the field capacitor
4) any wire #5(x)
5) main chassis ground stud
(With the battery connected, properly grounded and charged, you should only need to connect 12VDC(+) to one of the points listed for it).

Pick any combination that makes it the easiest and make the connection for only a couple seconds. You should experience a significant arc when you remove the wire used for flashing so make sure you don't damage any stud threads or braided brush leads in the process.

If I'm not mistaken, if the flashing circuit on PCB1 is good, you should see 12VDC(+) battery voltage on wire #219. unfortunately, I don't have a board circuit diagram to be able to offer much board troubleshooting.

[bmyers]

I will give this a try today. Thanks Duane!

[bmyers]

Ok, I flashed the field using a 12V battery and fired the machine up. It is generating and welding now. I used the actual brush studs to flash the circuit with a set of wires I made. I did not experience a huge arc when I did it, but I do not know how big it should've been. I tested the voltage at D2 between #4 and #5B. It was around 20-30 VAC. Anyway, it seems to be running and generating fine. So, the question I would ask is- how long will it go working before the field needs "excited" again? If this happens again and I flash it and it works again, that tells me I basically need a new board correct?


Thanks a lot!

[duaneb55]

If this happens again and I flash it and it works again, that tells me I basically need a new board correct?

Shouldn't have to unless you have an intermittent connection problem on the board (cracked solder joint) or bad harness connector terminal connection (dirty/corroded terminal).

Glad you got it working and keep us posted on its operation.

[bmyers]

I certainly will keep everyone updated on how it is working. I had all 4 110V outlets running something ( drills, hand grinders, etc, while welding with some 1/8" rods. I burned a few of them up and it did not seem to have any problem at all.

Havent tested the 220 outlet yet, as most of my stuff has a different plug than what the welder has on it.

Thanks again for the help. I have learned a lot, not to mention saved some hard-earned $.

[bmyers]

Went out today to get the cover cleaned up and put it back on and, well, it's doing it again. Last time I ended up re-charging or flashing the field and it woke up. I has only been around a week that it has sat. Nothing at all. No power, no weld, running good. Seems like the idler board may be giving fits, since I flipped it over to high idle and nothing changed. Any ideas?

[bmyers]

If it is the idler board, does anyone have a good idea what one costs? I am guessing I would have to order from lincoln.

[bmyers]

I have read that there is a capacitor that flashes the slip rings. If this is bad, there will be no output? If this is possible, where would this capacitor be found and how could I test it? Is this something that would be built into the board? Also, if this is the case, would it make sense that it ran after manually flashing it? If so, could I confirm it by maually flashing it again and seeing if it worked?

Sorry for so many questions! This thing is frustrating me because I thought I had it going.

Thanks

ben

[bmyers]

Re-flashed it again with a battery and away it went. Hmmm? I have pulled the capacitor, but do not have the right tester to test it. My multimeter will not test above 40 micro ferrads. This one is an 800.

[duaneb55]

I have read that there is a capacitor that flashes the slip rings. If this is bad, there will be no output? If this is possible, where would this capacitor be found and how could I test it? Is this something that would be built into the board? Also, if this is the case, would it make sense that it ran after manually flashing it? If so, could I confirm it by maually flashing it again and seeing if it worked?

Sorry for so many questions! This thing is frustrating me because I thought I had it going.

Thanks

ben
Ben, The capacitor you're referring to is the "Field Capacitor" shown in the wiring diagram on the next to last page in manual IM-368 for the unit and is labeled as such and C1. Its function is to stabilze rotor exciter voltage to provide a stable power output. It is not responsible for initial field flashing - although a shorted capacitor can be a problem.

However, I think you're going to find your problem is no initial flashing voltage from PCB1 on wire #219. The unit must see this voltage each time it starts in order to produce an output. You need to check for battery (+) voltage at PCB1 connector pin 2 and at the other end of wire #219 at resistor R3 with the unit running. You'll also want to check for (+) voltage after resistor R3 on wires #218A/218B that will be less than battery voltage. No voltage at either point indicates a problem with PCB1 as long as there's battery (+) voltage at PCB1 connector pin 1, wire #212.


Re-flashed it again with a battery and away it went. Hmmm? I have pulled the capacitor, but do not have the right tester to test it. My multimeter will not test above 40 micro ferrads. This one is an 800.
You can do a quick charge/discharge test with your VOM on the ohm setting. place the test probes on the capacitor and the display will increase. Switch the probes and the reading will go in the opposite direction. This is only a quick test and gives no indication of capacitance or leakage.

Check for flashing voltage from PCB1. I still believe you'll find your problem there.

[bmyers]

Thanks Duane! I will check tomorrow on the voltages. Thanks for the help with the capacitor. I believe it is probably ok, as I was able to test that it is/was not shorted out.

If PCB1 is in fact not putting out any voltage at #219, does that for sure indicate a bad board? Is it possible that R3 is bad and that could be causing problems with flashing the circuit?

[duaneb55]

If PCB1 is in fact not putting out any voltage at #219, does that for sure indicate a bad board?
About as sure as it gets if there is in fact battery (+) voltage at PCB1 pin 1, wire #212.


Is it possible that R3 is bad and that could be causing problems with flashing the circuit?
Hence the reason for checking for voltage after resistor R3 on wires #218A/218B. Resistor R3 should show a value of 10ohms across it if it's OK.

[bmyers]

Ok, with the unit running but obviously not generating, there is nothing at all at 219.

212 has 12 VDC with the switch in run position, and when the machine is running.

When I flashed the circuit, the machine would run and generate, and I had around 17 VDC at wire 219 at idle. When the machine kicked up to run something, 219 went to around 20 VDC. After R3 it drops down closer to 12 VDC.

Shut the machine off, checked a few things, and restarted, nothing again anywhere but 12 VDC at 212. One other wire that goes to the ammeter (208 I believe does have 12V).
I did not check 211, but I believe it may have 12 VDC as well if i remember right.
Nonetheless, wire 212 has battery voltage, which would indicate the board is gettingits power.

So basically it runs when it wants to, but then just quits generating power. Seems like the board may be bad, but the fact that it puts out voltage to flash the circuit when it is working has me baffled.

I also checked R3 for resistance and got 10.3 ohms. R2 checked at around 3.3 ohms, and R4 was around 3.8 ohms. R4 seems a little high but does not seem like just that would cause all this trouble.


Would a bad circuit or component in the board cause it to act this way?

[duaneb55]

Sorry to be so long getting back to you.

Your results indicate a bad flashing circuit on PCB1 which may be an open flashing diode (D8) or defective p-channel MOSFET - electronic switch - (Q1) on the board.

Diode D8 is easy to check by doing the following:
1) Remove control harness connector J1 from PCB1
2) With VOM set to "Diode" mode, probe PCB1 pin #2 with black (-) lead and #7 with red (+) lead. Reading should be between .200 & .900 if diode D8 is good.
3) Switch VOM test leads and reading should be .OL if D8 is good.
If step 2) or 3) fail, diode D8 is bad.

To check for output from MOSFET Q1:
1) Plug connector J1 back in to PCB1.
2) Select RUN position on RUN/START/STOP switch.
3) Confirm 12vdc(+) at connector J1 pin #1 (again).
4) Check for 12vdc(+) at connector J1 cavity #6 (no wire). 12vdc(+) here indicates input voltage to Q1.
5) Check for 12vdc(+) at connector J1 cavity #7 (no wire). 12vdc(+) here confirms output from Q1.
No 12vdc(+) in step 5) indicates a failed Q1 or it's non-functioning due to a failure in Q1 gate control circuit.

Any failed component can be easily replaced if you're comfortable doing that kind of work or there are a number of places that do repairs.

[bmyers]

Ok thanks Duane. Have been in the Seattle area all week for work but will try these hi gs when I return.

[duaneb55]

Forgot to include the board schematic and component layout drawings compliments of Lincoln engine drive troubleshooting tech Mr. Wagner. I had the schematic and the appropriate component layout drawing will confirm component location for you should you elect to repair it yourself or ???.

The schematic drawing lines are a bit hard to follow in a few spots so if you have any questions just ask.
64679
64680
64681

[bmyers]

Yes I will be repairig it myself upon confirming what the problem is. I have the tools necessary and access to some good help if I need it. One question for you is how to remove the epoxy coating?

[duaneb55]

One question for you is how to remove the epoxy coating?

Real high tech. X-AXTO or utility knife. Scrape it off, cut it loose. I also use solder wick to get the solder off.

[Horvik]

bmyers;

I bought a rebuilt P.C. idler for my Weldanpower at Stumpfs in Il. , they are online. It went for about 150 exchange, and it's been working good for 6 months now. They, also are good at helping a man out. My 2 cents after reading all the posts is check the output connectors where the ground and stinger go. A tear here can for sure cause them intermittant problems. Mine got twist connectors, they needed to be cleaned to make "good" contact.
With it not idling down, a low battery can cause this from what I have heard. make "sure" you got a full charge. Don't give up, she is a mighty fine machine, worth the work. Hope this helps.

[bmyers]

Hey Horvik, thanks for the help. Does that place have a website? I am going to try to rebuild the one I have, but if I can't, I would certainly be interested in talking to these guys.

[MadMax31]

Theres a Idler Board on eBay right now for 125.00. L6325

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=390223774872&ssPageName=STRK:MEWAX:IT

I was watching it in-case mine didnt work, but Im all-set...

[bmyers]

Yes I have been watching it. It is different than mine- probably for an older code, though I think it would work. I would have to remove the multi-pin connector and put spade connectors on each wire. I will attempt to fix mine before going to all that trouble. Thanks!

[MadMax31]

Just re-read for your code number, looks like yours is 2-3 years newer than mine, and likely has different guts... I tried

[bmyers]

Ok, had a chance to test it this evening. D8 is good. tested 0.547. Q1 is where I believe the problem lies. Had 12VDC at pin #1, and 12VDC at pin 6, but no output at pin 7.

How can I further test Q1 to guarantee it is the problem? Is there a way I can test the component itself while it remains in the board?

[Horvik]

Hey dere;

If you are still looking for a rebuilt Idler PC control board, i got mine through stumpfs welding , in downstate Il. Nice folks to trade with. On my Weldanpower I had the electrode side on the PC board down, the AC side worked.

Hope this helps
Ok, had a chance to test it this evening. D8 is good. tested 0.547. Q1 is where I believe the problem lies. Had 12VDC at pin #1, and 12VDC at pin 6, but no output at pin 7.

How can I further test Q1 to guarantee it is the problem? Is there a way I can test the component itself while it remains in the board?

[ccawgc]

testing on pcb is a yes and no. sometimes. A short is always a short. But do to parallel circuits, ohm readings can be off. A mosfet is metal oxide silicone field effect transistor.
The gate lead is not connected directly the transistor channel. So a resistance check would have a very high to open reading. The best way to test them is with a tester that uses battery voltage a resister and light and a switch to gate it on. Just look to see if there is agte voltage to it and the power it is controlling is there. If it doesn't turn on it is bad. For 5 to $10 just change it. If you remember what a vacuum tube was, the FET is functionally very close.

[Horvik]

bmyers488777;

How ya doin?

http://www.stumpfweldingsupplies.com/

Good folks, nah, I get no commision.
Hey Horvik, thanks for the help. Does that place have a website? I am going to try to rebuild the one I have, but if I can't, I would certainly be interested in talking to these guys.

[bmyers]

Thanks! I have the mofset on order. $1.50 for the darn thing. went ahead and got a few just in case. I will post updates when i get it in and get it all back together.

Ben

[bmyers]

Installed the Mosfet on the board and did some testing. I am really confused now. After testing the diode and replacing the mosfet, there is still no voltage at pin #7.

Oddly enough, when I first fired the machine up it worked perfect. When I shut it down and started it again, it had nothing. no power output, would not idle, etc.

There must be something else going on here?

Duane!????? I need more help!! :)

[bmyers]

anyone out there? I am lost for real now. It makes me think it may not be the board that is giving me problems, but the test still stands- no voltage at pin #7. This would indicate a bad mosfet? Or could there be something else on the board? Diode D8 tested good.

[GBM]

I am out here... but remember that old saying about ' the blind leading the blind' ? I am rooting for you getting it working ...and I am watching carefully in case mine starts to have problems...

[BCTimberwolf]

Hey ben, why don't ya just send that thing on down to me, seems like it's causing ya too many headaches. I'll just go ahead and remove that stress from your life for ya :D

[bmyers]

Im getting close but not there yet- I don't have much in it at the moment, though I couldve taken a night job at McDonalds and bought a nice Ranger by now with the time I have in it :). But hey, I have learned a lot, which is worth it to me.

[bmyers]

Shane, send me a pup from those wolves and I'll send that welder down- if that's you.

[BCTimberwolf]

haha they're both already fixed man. Even if I would have wanted to breed them I would have had to pay Timber's breeder $10k just to let him breed to an approved bitch

[ccawgc]

Out put is on pin 8. To get Q1 to turn on and supply 12 volts to pin 8 you need 12vdc from the start switch to be at pin 15 It goes to pin 2 on chip X1 comes out pin3 it then turns on Q4.
Q4 supplies a ground to a resistor network R35 -38 and R8, wire 212 supplies 12vdc to the R8 and Q1. put volt meter across Q4 and see if it goes from 12vdc to near 0 while cranking.
If not work you way back to pin 15 and see what doesn't change state.
Q4 has to turn on before Q1 can turn on.
X1 is a NOR gate. (If I remember my TTL logic symbols correctly) It sees the start switch and 115 volts. should turn flashing off when 115 volts is available.

[duaneb55]

Pin 8? Per control board drawing M15506 for Ben's unit, initial flashing output is thru diode D8 on pin 2, wire 219.

[bmyers]

I am certainly confused now lol. Could Q4 be causing the problem then?

I see on the schematic that pin #2 is labeled as the "Reset" circuit. Is this what the flashing circuit is called? Q1 and D8 do appear to be labeled as the flashing circuit on this diagram.

Where to go from here? I obviously need to do some more testing, just not sure what yet. What are the chances there is a problem in the hard cicuitry of the board itself? I examined it very closely and see nothing that looks even suspect.

I attached the schematic again also.

thanks
ben

[duaneb55]

Q4 is associated with the flashing circuit portion of the control board and wouldn't be affecting the auto idle portion that includes X2 that has the pin 2 that you referenced correctly as "Reset". X2 is the logic chip that controls the Auto Idle. I was referring to the control board connector J1 pin 2.

I have to be honest and say at this point I'm tapped out with regard to long distance trouble shooting on this one. Too many variables that can be contributing factors and I could very easily have you spinning your wheels even more.

Hopefully ccawgc will have a better idea where to go next as I trust he has more experience and available information on this matter.

[bmyers]

So if I understand correctly, it could auto-idle without generating any power? I would think the 12v from wire 212 would give power to the board, which would route a different power source to the magnet itself on the idler.

If that was true, when there was not generator output it would not properly idle down. I stated in an earlier post that it idled but did not put out any power, but I believe I was incorrect- near that same post I asked about adjustment. When it is generating it actually idles down properly- I in fact had to turn the idle up a bit according to the mfr. specs.

So it sounds like it this is right, maybe Q4 is a potential target? Let me know what you think- and how to confirm it if possible....

Thanks again for all the help,

Ben

[ccawgc]

You right flashing circuit out put is pin 2. That's what I get for working on this late at night.
What I had described was the function of the flashing circuit.
Now the auto idle Is a different story, Is this a pull to high or pull to low.?
As noted Pin 2 on X2 is the reset for the timer. 2 different signals can reset the timer.
One from the current sensor and the other is from the start / flashing circuit.
Drawing current or pushing the start switch will cause the timer to reset.
They want the welder to go to high speed when starting the engine. It should then time out and go to low speed. Lets do basics. find the 10VDC power supply lower left corner of the diagram. Test from circuit 5E (ground) to the cathode (stripe) of D10 Or find DZ2 and c10.
and measure across them.
The circles with a voltage next to them are power supplies. arrows connect to the circles.
If this power supply is bad nothing on this pcb will work right.
See if the 10vdc is there and report back.

[bmyers]

It's is a pull to low idle. It let's loose to full speed when it isn't magnetized. I will reread the post and so some testing when I'm home. Then report back.

Ben

[bmyers]

Ok,

With the switch in run position:

D10 cathode side to ground: 10.07 VDC

DZ2 cathode side to ground: 10.07 VDC

C10 (bottom side): 10.08 VDC to ground

Another thing I wanted to ask is which wires on the main connector should have 12 VDC, just to make sure I dont have something connected wrong.

With the switch in the run position and set to auto-idle,

212: 12VDC- I know this one should have it.

215-12 VDC- not sure here? It goes to the idler solenoid at the back of the machine.

208- 12 VDC this one goes to the ammeter on the front. I think it makes sense.

213A- 12 VDC- looks like it goes to the auto idle switch and picks up 12 VDC from wire 212B.

211-12 VDC- from the main start/stop switch

I attached a snip of the wiring diagram

[duaneb55]

Ok,

With the switch in run position:
D10 cathode side to ground: 10.07 VDC
DZ2 cathode side to ground: 10.07 VDC
C10 (bottom side): 10.08 VDC to ground
This confirms the board has 10VDC logic power ccawgc referred to.


Another thing I wanted to ask is which wires on the main connector should have 12 VDC, just to make sure I dont have something connected wrong.

With the switch in the run position and set to auto-idle,

212: 12VDC- I know this one should have it.
Correct.


215-12 VDC- not sure here? It goes to the idler solenoid at the back of the machine.
With the control board not calling for low idle (ground to #215), 215 will have 12VDC as a result of feed thru the idler solenoid coil from #213.


208- 12 VDC this one goes to the ammeter on the front. I think it makes sense.
#208 is the battery charge output from the board so yes, 12VDC (+) from the battery (+) thru the ammeter to 208 is correct.


213A- 12 VDC- looks like it goes to the auto idle switch and picks up 12 VDC from wire 212B.
Correct. #213A and 213B is a common connection point for 12VDC (+) with Auto Idle switch in the ON position to the idler exciter relay C2 and flyback diode D7 located on the board.


211-12 VDC- from the main start/stop switch
Same situation as #215. 12VDC (+) will be present on #211 as a result of feed thru the cranking relay coil CR1 until the RUN/START/STOP switch is placed in the START position to supply ground to CR1 to crank the engine.

[bmyers]

Did some more checking and rereading today. I think I may have an idea of what the problem is, but no idea of the cause at this point. Earlier in the thread I checked pin #6 and #7 at connector J1 for voltage. Pin #6 indicated input voltage to Q1, while #7 indicated output. I replaced Q1 with a 6A 100V P-channel MOSFET, and still nothing at pin #7. I replaced it again with another new one I got, and still nothing. Diode D8 tested as dropping .5xx volts before. I will test it again, but Duane mentioned something about the control cicuit having a failure or the MOSFET being bad. What else is there in the flashing circuit besides these two components that could cause the problem? Are we still sure there should be 12 VDC at pins #6 and #7 with the run switch on "RUN"? According to the schematic, it looks like this should still be a place to check.

Thanks again!

Ben

[bmyers]

Should I try replacing diode D8 anyway? On the schematic, it specifies all diodes are 1A, 400V UOS. The diode for D8 is 1N5406, which is a 3A, 600V diode. Is that correct?

Also, I it possible that Diode DZ8 could be bad and cause this problem?

[ccawgc]

D8 is an easy test, Test it in diode test. DZ8 Should have around 10 volts when Q4 is turned on. logic gate X1 A has to be turned on by the start button, which in turn, turns on Q4.
Q4 connects the resister string to ground and turns Q1 on.
DZ3 and DZ9 are for noise suppression. Since They are rated for higher than 12 volts.
The diodes with the DZ symbol are zener diodes. They can be used as voltage regulators for power supplies or as filter/limiter. which prevents the voltage in a circuit from exceeding a voltage set point. Put your meter across DZ9 and push the start button. Tell me what you get.
Then read DZ3 and do the same thing. Voltage before and during cranking.
Check DZ1 the same way. Should be able to tell you the bad part.

[bmyers]

I checked all the diodes on the line side tonight on the board. First thing I noticed is that I think we are using 2 different diagrams. I have attached the one that matches my board. I noticed the other night that the one I attached before is not the same- none of the resistors and other things are the same. Also, I have no DZ9. Anyway, here is what I found, going from the top left of the board in rows:

D10: 10.1 VDC in run, 8.4 cranking

D11: 12 VDC in run, .4 cranking

DZ7: 0.6 VDC in run, 0. 59 VDC cranking

DZ1: 8.4 VDC in run, 0.6 cranking

DZ4: 5.4 VDC in run, 6 VDC cranking (this one was dropping when it was in run)

DZ3: 12.2 VDC in run, 0.6 VDC cranking

DZ2: 10 VDC in run, 8 VDC cranking

D1: 80 mV in run, 80-100 mV cranking

DZ8: 12 VDC in run, 9 VDC cranking

D8: 0 VDC in run, 8 VDC cranking

DZ5: 12 VDC in run, 8 VDC cranking

D7: 12 VDC in run, 8.5 VDC cranking

D9: 10 VDC in run, 9.2 VDC cranking

DZ6: 12 VDC in run, 10 VDC cranking

D14: 12 VDC in run, 10 VDC cranking

D15: 5 VDC in run, 6 VDC cranking

D12: 12 VDC in run, 9 VDC cranking

Not sure what is expected of these, but it seems that DZ1 and DZ3 should not lose so many volts upon cranking. Maybe it's right, I obvously don't know. I have attached the schematic that matches my board, unfortunately it does not have circuitry, only components. I also attached the other 2 I got from Duane. The one that matches my board is L7607-2. The other one, L7607-3, is from a different code number. The circuitry schematic M15506[1], is from something else also.

Thanks again!

Ben

[bmyers]

Duane your source wouldnt happen to have the circuitry for the 7067-2 board would he?

[duaneb55]

Ben,
I haven't had a chance to attempt to digest your test figures as yet and perhaps ccawgc will jump in and offer his insight.

As for the circuitry for the 7067-2 board, the difference between it and the 7067-3 unit is it used single larger resistors in places where the "-3" version used banks of smaller multiple ones - from what I can see. I recieved all the drawings from a most helpful Lincoln Customer Service technician whos name escapes me at the moment.

[bmyers]

Ok, I will keep that in mind. I can understand how the resistors were used and how 7067-3 is similar, in fact I could see it working possibly on my machine if I had one. Only problem I have is that the other diagram with the circuitry is somewhat different. I have noticed at least one diode downstream from the logic board and timer that is on the circuitry, but is not on my board anywhere that I see.

[duaneb55]

No good on the logic schematic for the former L7607-2 board. Lincoln doesn't have it per the gentleman in Customer Technical Assistance that provided the other drawings. I think he told me that before too.:o

One would have to map out an existing board to re-document it.

[bmyers]

If it will help, I can do it, or at least try. I really want to fix this thing but have tried more than I know. Learning a lot though!

[ccawgc]

Sorry guys, was very busy over week end and could not get near the computer. see next post.
The 7067-3 board will replace the 7067-2 and work fine. As a rule a higher dash number will replace a lower dash number and work normal.
Now I see where there is some confusion. I think you will find the basic circuits are the same.
The changes will be in filter caps, added or removed diodes and resister size. Lincoln has an on going program that revisits pcb and machine designs and they see if they can reduce their cost to produce the parts and machines. No more changes are made when they no longer make a given welder. Unless a part they use on a pc board is no longer made. But there has to be a demand for more replacement boards for they to come up with another board.
Limit your circuit tracing to just one circuit. Flashing circuit. start at J1-pin 15 follow it to chip X1 pin 2. See if the out put changes at pin 3 during start. Then to the small transistor Q4.
With DZ 3 dropping to 0 during crank we should be working to here. Dz3 goes to 0 because Q4 is turning on. Other voltages that are dropping to 10 could be that your battery is dropping to 10 volts while the engine is cranking.
DZ4 is in the battery charger and the voltage there will change as the battery charges up.
I am going to print out your diode test post and look at the diagram a little closer.
But for now limit your testing to the flashing circuit until you get it working and then we can think about the auto idle. You bouncing around it is hard for me to follow.
Where you located again?

[ccawgc]

After looking at your diode voltage list It looks like the flashing circuit is working. But the voltage on D8 appears to be to high. The voltage drop on a diode is 0.7 to 1.5 volts, the transistor Q1 should be around 0.7 , since D8 is a three amp diode the flashing current will be less than that. I guessing around 0,75 to 1 amp
Lets check this assuming the battery voltage is dropping to 10 volts during crank and the flashing current is 0.75 amps.
The voltage on the rotor should be 2.5 vdc and R3 will be 6.5 vdc leaving 1 volt for Q1,D8 and bridge diode D2. (R3 and D2 are out in the welder).
Right now I am guessing either D8 is bad or there is a short in wire 219 to ground. Find R3 and measure it.( 10 ohms) measure wire 219 to ground. check for ohms then do a diode test (black meter lead on ground) and report back. unplug the pcb when doing the ohms test.
Check your battery voltage during crank , then the voltages on R3 and D2(neg brush to ground), brushes. Used Ohm's law to figure out the different voltages.
I hope this is not confusing.

[bmyers]

Finally got some time and getting ready to look at this. I am located outside of New Richmond, IN. Let's ignore the auto idle for now since it seems to work when the machine works. Didn't mean to jump all over the place, I was just quite clueless when I started this project and tried listing things I didnt think were right. I will check the things you said and report back. THe voltages calculated from Ohm's law make sense to me.

Ben

[ccawgc]

I just hope after all this we do not have the dreaded flying short in the rotor and a intermittent one at that. The flying shorted rotor is a rotor with a loose wire some where. Tests good at rest but the wire moves at speed and contacts ground. Causes all kinds of problems.

[bmyers]

Still going to do some more checking but last night I was testing some stuff and started it up and it worked flawlessly for awhile. I shut it off and repeated starting it and it worked over about a 3 hour period every time. Left it alone and changed absolutely nothing. Today after work I started it again and it's absolutely dead. 219 and all 218 wires are not shorted. 218 has around 850 K ohms to ground. With the unit running or during cranking there is nothing at D8 and nothing at R3. 9 mV is all I got at either place. R3 tested 10.3 Ohms as it was before. I am going to try and diagnose your posts and get exactly what you were after, but I am still stumped as to why it has been working so intermittantly.

[bmyers]

Also, the battery does in fact drop to around 10V when cranking

[bmyers]

Ok, WHILE IT WAS WORKING YESTERDAY:

R3 had 4.8V cranking on the 218 side, 11V on the 219 side. This was as cranking and shortly after it started.


Today:

Nothing anywhere in the flashing circuit except for Q1 had 12V on both of the outside pins. These voltages were present during crank, when it sat in the run position, and when it was running.

D8 was dead but for about 9 mV. 219 had around 8 mV.

Negative brush to ground was 0V. R3 obviously had nothing.

Something is causing the flashing circuit to work intermittantly with no pattern whatsoever. Before, Diode D8 tested good, I will test again but have to borrow a different meter like I did before. My meter does not test diodes.

[ccawgc]

Lets try some thing. Mark the brush wires and remove both of them. Tape them.
Clip on your ohm meter to the brushes. Make sure the leads are routed so they do not catch on anything that moves. Start the engine and read the resistance of the rotor while it's turning. You said it was 4.4 at rest. Lets see what it is while moving . This will tell us if a brush is loosing contact or the rotor is opening or shorting while turning.
Next do the same test from each brush to a good frame ground.
Also check wires 201 and 5 at D2. Make sure none of the wires are broken in the crimp.
I am thinking you have a intermittent ground connection to the rotor or a bad rotor.
out of round slip ring causing the brush to loose contact. Double and triple check all your connections in the rotor control and flashing circuits. Something looks OK and tests good some of the time and then changes. Back to square one we go. Connect your meter to a small area under test and give it the yank, twist and pull test on the wires. See if you can get it to show up. Keep this in mind. Electricity travels in a circle. You must have a complete circle from the positive battery terminal through all the parts and wires to the negative battery terminal. Break the circle at any point and it stops working.
When you loose the ground to the rotor you should get readings like you got. Q1 might not even turn on. when it is not working, take a measurement from one end of R3 to the other.

[bmyers]

Back to square one we go. I will get on this as soon as I can. ISO audits at work start tomorrow so I could be in for a long week yet. Thanks a lot so far!

Ben

[bmyers]

With the meter leads clipped to the brush wires, I got 5.5 ohms sitting. Running it is all over the place- does not stay constant, but that could be my meter. Sitting I got around 5.5 through the brushes and 4.4 on the rotor itself anywhere I rotate it.

I cannot find any breaks in the pins on D2 at either #5 or #201.

One thing I did notice is that as it sits right now, wires 4 and 4a are grounded. Should this be?

[bmyers]

Also with the machine sitting, all of the wires going to the 110 outlets are grounded. Is this common?

I have checked and cleaned connections, checked for broken leads, etc. Still nothing.

[ccawgc]

wire 5 is ground wire 3 is 115 volt hot. see where they come from. wire 4 also goes to the same winding. To explain what is going on If you take a wire a wrap it around a pencil 20 times. Take a second wire and wrap it 20 times connect the two coils together, add a third coil and connect it. Now all 3 coils are in series. If I connect one end to ground. then any where along the series of coils I connect to it will measure a short to ground. This is because the coils have little resistance to DC voltage the meter uses. and is normal.
To test for shorts in these type of circuits you have to remove the known ground.
You do need to know all these connections are good and not shorted or open and the connections to D2 are good .
How much was the rotor Resistance changing while running?

[bmyers]

I had a chance to hook the leads up to the brush wires again. I turned it by hand and checked the resistance all around.

Turning it slowly by hand, it stuck right around 5.0-6.0. If i spun it some quickly, it would jump up some but always stop back within that range. I turned it couple degrees at a time all the way around and could never get it to stop at anything higher than 6.1.

Spinning quickly it jumped as high as 16 or so, but like I said went down to around 5.5 when I stopped and I could not find the high spots again.

Am I doing this correctly? When the machine is running it bounces so quickly it is almost not readable. This could be my meter. I am new to a lot of this obviously. I just want the darn thing working. I also am nto understanding how a problem in the rotor will cause the flashing circuit to work intermittantly.

[bmyers]

Is there anywhere I can send the board in to get it tested? Or anyone have a working machine with the same code who would be willing to try it in theirs if I shipped it?

[ccawgc]

Any reading from the brushes to case ground at speed.?
The rotor is the rest of the flashing circuit. It must not be shorted or open at anytime for the flashing circuit to work. A transistor will not turn on if part of the circuit is open.
Some rotors will test good at rest then open or short out at speed. drives us nuts.
duaneb55 can you help with making sure the rotor is not part of the problem
He has a intermittent connection some where.

[bmyers]

I wilk check them to ground tonight. Forgot about that.

[duaneb55]

Let's back up a step for a minute.

In post #20 you said the unit would weld and generate after flashing the field. Is that still the case?

If so, the rotor and stator windings are fine and the problem is definately in the field flashing portion of PCB1 or within the external flashing circuit which includes only R3 tested earlier in the thread and the ignition switch which also checked out OK, wires #212, 219 and #218A and the PCB1 harness connector with its terminals.

[bmyers]

Just got back in for the evening and have not had a chance to take a look at it. This weekend I plan to take a few steps back and retest a couple things- the ignition switch, manually flashing, etc.

One question I would have for one of you is how on earth this thing would lose it's magnetism or "flash" so quickly?

Someone told me that years ago genwelders did not have flashing circuits. When the manufacturers went to a different alloy of steel that would not hold magnetism, flashing circuits became a necessity. He told me the alloying element but it escapes me at the moment. any truth to this?

[duaneb55]

These units - as many others do - require flashing each time it starts up as they don't rely on or maintain residual magnetism as some types do. No flashing, no output. Simple as that.

[ccawgc]

I was rereading some of the posts. You can flash it and make it work.
It has started up and worked on its own a few times.
Rotor is good, but you have a bad connection in the flashing circuit. It is either a short to ground or it opens up.
Check all the plugs and connectors. Plug the pcb plug and check the pins and sockets.
Make sure they are all in place and the sockets are not enlarged. I have seen sockets get enlarged during testing when a meter probe is pushed into it.
Keep digging it is going to take a little luck to find.

[bmyers]

Finally, I got a chance to look at this again and possibly figured some stuff out. Still confused nonetheless. I flashed it Saturday and it still did not work. I believe this is because my jumper wires are not making a good connection to the brushes.

I started it today and it worked perfect, so I let it run and started some more checking. I also mapped out part of the board by hand. I do not entirely understand how a MOSFET works, but I believe Q1 is not turning on all the time for some reason. Saturday when it wasn't working, Q1 had 12V on the top and bottom wires. Also, there was no output at pin #7 of connector J1.

In previous posts, Duane noted that #6 was the input and #7 was the output for Q1. Is this still correct? It makes sense to me.

Today when the machine was working, the top wire on Q1 had 2.6V, and the middle and bottom both had 12V.

Based on the mapping I did, which I can post if it would help, the center wire on Q1 runs out through Diode D8, and down to pin #2 (Wire 219). It also loops around directly to pin #7.

It appears as though something is not turning Q1 on all the time. I am guessing we should be able to trace it back to Q4? When I did all the testing before, it seemed fine, but obviously isnt working all the time.

Are there any components on here that could work intermittantly? I figured they'd either be good or bad.

Sorry if this confuses you guys more. Let me know if there is more I can do or check. I will go ahead and post a scan of the flashing circuit tracing I did.

Ben

[bmyers]

Here are the maps. Pretty crude, I know. One has the mapping I've done so far. The other has it with the middle wire on Q1 and it's circuitry traced in red. Let me know if there is more I can map that would help.

Also, I understand there is a source, gate, and drain on a mosfet. Which is which on here and does it seem right?

Thanks again,

Ben

[bmyers]

I checked the leads to the brushes for manually flashing and they are in fact not shorting out. I flashed it several times and it seems to make no difference on whether or not the machine is working. Earlier on I had flashed it and it did work, but I cannot figure out if it was coincidence or not.

It seems that whatever the problem is, it either all works perfect, or nothing works at all. Today I had it working every other time I started it. Works, doesn't, works, doesn't, etc.

Let's go way back to when I had it apart and fixed the oil sump pan. I had the engine completely off of the unit. Is there anything I could've knocked loose that is extremely hard to find? Everything in the front is hooked back up and tight. I believe I got it back together right for a number of reasons, the main one being that it works and welds some of the time.

The thing I do not understand is that when it isnt working, it does not even make an attempt to flash itself. It also does not idle down correctly at all. The only two things it has are input voltages to the board, and the engine running.

I tried jerking on wires, checked every conenction I could find, plugged and unplugged stuff, and I cannot seem to figure out what is making it work or not work.

It seems if it were a problem in the rotor or windings, it would still attempt to flash itself, but to no avail. It also would seem that if that's the case, manually flashing it would make it work.

What would happen if I were to hook a constant 12V up to the brushes and give it a try? I never saw wire 219 lose voltage while it was working and running.

[duaneb55]

I'm thinking bad RUN/START/STOP switch that makes intermittent connection between wires #209A and 212 - which is required for the necessary initial flashing to take place. Just a guess.

If you were to connect 12VDC directly to the positive brush, you would need to disconnect it once the unit started or install a diode to prevent a high voltage backfeed to the voltage source once it started producing power.

[bmyers]

would that be 209A and 212 upon starting or with the switch on run? I see what you mean about the diode also.

[ccawgc]

To test the rotor. If you jumper battery voltage you will need a blocking diode.
Or disconnect both brush wires and connect a variable DC power supply.
With it, you can control the welder output. Put and volt meter on the brushes and a amp meter inline. This way you can weld or draw a full load. watching the current draw on the rotor . This way you know for sure the rotor has not been damaged.
Do check the run-start-stop switch. Old switches have a bad habit of being intermittent.
We use a variable transformer and a bridge diode for our DC power supply.

[duaneb55]

would that be 209A and 212 upon starting or with the switch on run? I see what you mean about the diode also.

Switch in RUN position.

[bmyers]

Switch tested fine. I clipped the leads on and had it in continuity mode and pecked on the switch, shook it around, etc, and could not find any reason to believe it is in the switch.

What I did do is while it was running, not generating power (never worked on it's own today), I took my tester probe and jumped the top wire of Q1 to the middle one (sent 12 to wire 219). The machine immediately idled down to low idle. Picked up the grinder which I have plugged in and turned it on, and it snapped back to high idle and continued to work.

While it idled back down I checked again, and Q1 was still not putting anything out on the center wire. I still think whatever turns Q1 on is what may be bad.

Any thoughts?

I have the whole front off and everything again, and have continued to check every connection again and again, cleaned them off, rechecked R1, R3, etc. I still think that if it does not at least TRY to flash itself upon startup, there is no sense in messing more with the hardware on the machine itself. It needs to be sending voltage to wire 219 all the time first, then if it is getting a flash but not putting out power, we can go from there. The flashing circuitry should only be dependent on input power to the board until voltage is sent to wire 219, or at least out pin #2 on J1.

Let me know if I have stated this correctly, and what the next thing to test would be to narrow it down.

[bmyers]

Sorry did not clarify, when i turned the grinder on, it worked.

[ccawgc]

219 should only have flashing voltage for as long as the switch is in start and it will turn off with the release of the start/run switch or 115 volts at the plugs. Which ever happens first.
So Q1 should turn on then off and Flash The rotor. Like flashing a flash light. You do not need this voltage once you have output. The excitation and output control takes over to control the welder output. Check you private message.

[ccawgc]

Shorting pin 1 to pin 2 just turned Q1 on for as long as the short was in place.
shorting pins 2 to 3 bypasses Q1. Pin 1 is the gate pin 2 is the drain pin 3 is the source.

[bmyers]

So any idea what component turns Q1 on and how it can be tested?

[ccawgc]

Q1 is turned on by Q4 turning on. Your post #65 shows a test across DZ3 which is parallel to Q4. In run you had 12.2 volts which is correct. when you go to start, the voltage dropped to 0.6 volts. This shows that Q4 has turned on. Should stay on until voltage builds in the power plugs or start switch is returned to run.Then it turns off.

Please check you private message and get back to me.

[bmyers]

I sent you another email ccawgc. Will pm when I get to a computer.

[bmyers]

welder is back together and has been working. Still never found for sure what the problem was, but I know what to look for now. The flashing circuit was not being "told" to come on- at least that is my best guess. With more help over the phone from ccawgc, I now know exactly what to check and why. He and Duane are both very knowledgable guys providing help on here that is priceless. Thanks again!

I cleaned all the grounds and checked the main switch again. I am thinking there is an intermittant problem in a ground somewhere, probably wire #211. Start-stop-run switch takes wire 211 to ground upon starting, which grounds the solenoid, turns the starter on, and tells the logic to switch Q1 on (at least I think so). Since the starter solenoid always comes on, I am thinking the problem may be in wire 211 between the board and the switch.

If it acts up again, I will try replacing that wire, possibly wiring in a toggle switch to manually ground it after starting. For now I burned up a handful of 3/16" 7018's at around 220 amps while running something on all 4 110V outlets. Never missed a lick.

ben

[GBM]

For now I burned up a handful of 3/16" 7018's at around 220 amps while running something on all 4 110V outlets. Never missed a lick....Ben

That is very exciting.... I am just getting Mason vibration isolators mounted under mine.... will try that same thing as soon as possible...I hope mine works well.... because I do not think I could go through what you have to get it working again....
Greg