Reply to Thread

Re: Lincoln TIG 200 Square Wave repair

Would someone here know what components to check for my failed Squarewave 200: welder only works up to 90 amps on stick and 125 on tig while powered at 230v. I was stick welding at 130 amps, heard a loud bang from the box and the current dropped to 90A. I have board repair experience so if it's not too difficult to id the problem I can probably fix it. Thx for any assistance.

Re: Lincoln TIG 200 Square Wave repair

and someone on this site that repairs machines even said them small lincolns were dropping like flies

Re: Lincoln TIG 200 Square Wave repair

Originally Posted by shovelon

I am very happy with mine.

the LWS has three dead ones in the back room. that tells me all i need to know

Re: Lincoln TIG 200 Square Wave repair

Originally Posted by mb443

You may want to post a picture with location of C12 that you have blown up. As of why capacitors blow up, then normally two reasons. First over voltage, and if this is not the case then just simply bad quality and need to be replaced.

My understanding is that capacitors on the boards are to prevent brown out conditions on the circuit boards and microprocessors under surge. They have replaced the PFC capacitor banks that were found on many old style tranny welders as opposed to the new inverter welders. The capacitors can lose charge if sitting idle too long and really need a top off before welding. Usually 5 minutes will do it, but if sitting for months precaution dictates a good 30 minutes. Capacitors if bled way down deteriorate IMO, so keep them charged. Fully charged they protect the fragile boards from brownout sizzle failure.

I am not an electronics tech, just an old weldor that killed off many tranny and inverter weldors. YMMV.

Re: Lincoln TIG 200 Square Wave repair

You may want to post a picture with location of C12 that you have blown up. As of why capacitors blow up, then normally two reasons. First over voltage, and if this is not the case then just simply bad quality and need to be replaced.

Re: Lincoln TIG 200 Square Wave repair

Any ideas? Thanks

Re: Lincoln TIG 200 Square Wave repair

Originally Posted by cornchip

as many posts as theres been about them small lincolns i dont see why people keep buying them. where you located ? ill sell you my invertig221

I am on the other side of the fence on that. I have one on wheels that I drag across my shop for tacking alum and steel sub assemblies every week. I also use that same one for my welding workshops when I have 10 college kids at a time doing a deep dive into tig. I also drag it onsite for weld repairs in defense plants that take the serial numbers and authorize it's use. I may be taking it out to Port Hueneme in January if I can get a security clearance. My kid has the other one in his home building performance parts for air cooled Volkswagens. Neither has had an issue.

I was also involved in product testing for Harbor Freight who basically sourced the same warehoused Lincoln parts out of China and put out the Vulcan200 until Lincoln sued them with a cease and desist. My BIL is using that one in Arizona. Many, many thousands of these Lincoln and Vulcan units have been sold and are in service. They are strong and robust and designed for the novice.

I am very happy with mine.

Re: Lincoln TIG 200 Square Wave repair

And to add to the C12 capacitor ID, what would make it blow, overload, defective, other component failure overloading it?

Re: Lincoln TIG 200 Square Wave repair

Can anyone help me identify the value of the C12 capacitor on the HF board of the Tig 200? Thanks

Re: Lincoln TIG 200 Square Wave repair

Sorry for late reply, all pictures posted below and yes, that is crescent air gap around pin2 of U07 that I was talking about. And you have to remove the board to get to the comfortable position to solder new parts.

Re: Lincoln TIG 200 Square Wave repair

plz post your schematic that you mentioned to share with others as I did all over this forum, would be nice if you do...

Re: Lincoln TIG 200 Square Wave repair

U07 is the switching power supply power chip which provides 15V, next to PFC board on the main board, with green LED. Relay shorts current limiting resistors which used to charge electrolithic capacitors, then as soon as they charged the full current can go to power IGBTs inverter.

Re: Lincoln TIG 200 Square Wave repair

Hi dryfeb_engineer, the reason you don't see any voltage on primary part of the opto coupler could be the reason for thermo regulation circuit is having issue with power provided to U03 which I'd check first.
if Vcc is there then I'd consider replacing U06 optocoupler. But before you do that, check also, if voltage is present on U03, then check on pin1 signal while trying to heat Q18 a little to make sure it reacts on temperature changes. if no changes, consider to replace U03 (358) op amp. There is also a dependency on signal from U09 coming to pin3 check it first before rendering 358 as dead and to be replaced and drop here details of your findings.
Good Luck Mike B.

Re: Lincoln TIG 200 Square Wave repair

You may want to test your board on someone's working unit if available, or worst case may need to replace your display board with new as it contains a CPU which need to be reprogrammed and firmware is not available around. The good part is that it wasn't crazy expensive back to when I bought my unit.
As of power supplies to check voltages there one U1 (5M380R) and two +- 15v 7815 & 7915 next to each other. You can also see that part of the board on the picture I published earlier on 12/21. See first there on any burned components, and yes you may need to take calk out around those parts first.
Unfortunately, that's as far I can help as I never had any issues with dark display board so I can only guess...

Re: Lincoln TIG 200 Square Wave repair

Hi 80pickup, assumed that there is +15v on next to PFC board and green LED is on, (since FAN is blowing) I'd begin with checking voltage on processor/display board, download datasheet for chips on that board and check all voltages (GND and VCC) pins. If nothing on them then there are few power supplies similar to power supply I described, on the main board next to the display board need to be checked. Good luck! Mike.

Re: Lincoln TIG 200 Square Wave repair

as many posts as theres been about them small lincolns i dont see why people keep buying them. where you located ? ill sell you my invertig221

Re: Lincoln TIG 200 Square Wave repair

Hey everyone. I justed joined this forum as I was searching the web for others with issues with their square wave 200. I live remotely have no hydro but use a 7200 watt Yamaha generator to run my square wave. When it was under warranty it pooched and olny produced the faintest spark. Contacted Lincoln and they took care or some warranty work and got me going. Since then worked very well, then after the warranty period was up it did the same thing. Fan run fine but just the faintest spark comes off it. I know someone will say because I am not using an inverter generator that is my issue but I have a hard time with that. I also have a kicking horse plasma cutter which I use but not to its fullest extent because of lack of power to run it fully and never have issues with it or a mig welder I have. I know it most likely is the board is not designed to run off the generator. Recently I spend days and days searching and found a cool tig 220 which on their you tube videos state they engineered their welders to be run off non inverted generators so I bought one. It works fantastic so far but I would like to fix my Lincoln so I phoned and the parts guys says $1750 roughly to fix it for the board. That’s more than I paid for it originally I tell him. Inflation is his answer��*♂️
long story short I have not pulled the cover off yet to look at it. This winter when the lake freezes up and I can get back to my house I will pull the cover off and take a look. Has anyone else been running their squarewave off a generator and had this issue, and anything I should check right off the start. Thanks for any help you can provide. I look at some of the responses and I don’t have much for electronic diagnostics equipment

Re: Lincoln TIG 200 Square Wave repair

Hey MB I see you still comment on this thread somewhat regularly so I've got a question for you, I've got a machine i acquired recently that when plugged in and turned on the white light comes on and the fan comes on but nothing on the screen. I've taken it apart and looked for anything obvious and seen nothing as well as peeled back the silicone in the area you documented and don't see anything clearly burnt or bad so I'm curious what testing you think I should do to get to the bottom of the problem. Much appreciated if you do respond as I know the thread is quite old at this point

Re: Lincoln TIG 200 Square Wave repair

I checked the voltages at U06 when in operation and I measured 0vdc across pins 1 & 2 (input of optocoupler) and 14vdc across pins 3 & 4 (output). I am assuming this is the “Off” state.

Not sure what the function is of the other Optocouplers are directly below (U05, U04, U10) but they all measured 1.14vdc across the input side and 0vdc across the output side. I am assuming these are all “On”.

Any thoughts?

Also, do you know how many temperature sensors are installed on this model of welder? So far I have located two of them.

Re: Lincoln TIG 200 Square Wave repair

hello, the CPU is on the display board and there is a model of it there on the picture of the board, but I never worked on those.

Re: Lincoln TIG 200 Square Wave repair

PCB - printed circuit board for short.
How is it going with your repairs, sorry I wasn't checking on this thread for a while.
I guess you've already replaced your caps and checked on the rectifying diods.
Please update here how it was repaired if it was...

Re: Lincoln TIG 200 Square Wave repair

Hey dryfeb_engineer, take a look at the fragment of Thermal Control above, may help. U06 there is a optocoupler you may want to chekc if all before that if function and reacts to temp change.

Re: Lincoln TIG 200 Square Wave repair

I have a Lincoln Squarewave Tig 200 that continuously indicates a Overtemp condition (yellow led is on). The displays and fan are working fine but it won’t operate. Has anyone had this issue and what is the fix? Any idea how to test the Overtemp sensor?

Re: Lincoln TIG 200 Square Wave repair

Unrelated to the debug...

I was hoping to get pictures of the microprocessor board. Would love to see if we can figure out exactly which microprocessor they use & what kind of SPI flash is used to store the firmware.

Also, was hoping to get pictures of the solenoid for the shielding gas.

Re: Lincoln TIG 200 Square Wave repair

What were the symptoms of your machine mb? I recently acquired one. It powers up, no fan it will strike a small arc but then start powering the display on and off. If I unplug it then recover it it lights up, resets to stick but repeats again if I try to start an arc.