bad powermax 380 circuit board

[steve w]

I have a powermax 380 and the circuit board has gone bad. I called Hyperhterm tech support and the technician did a great job of helping me diagnose the problem. We changed all the parts in the torch with new consmables and nozzle cap, sirl ring and o-ring, all were hyperhterm orginal parts. But I get gas flow but know arc from the torch when I press the trigger. The power light stays on solid but the torch lights begins to blink when I press the torch trigger and stays on until I reset. We ohmed out every wire in the torch lead and all are good and the ground lead. I also pulled the handles apart and all was good. We checked the plunger in the head of the torch and he helped me check the ohm values on all the rest, and all is in range. We checked other voltages on the board and all was good. But their is no DC voltage coming from the board on the torch terminal (torch white, L2 Red), and the ground terminal when I press the trigger. I have had it 8 yrs but very low hours of use. I have loved using it when needed and would still like to fix it but a new board is around $870.00. I was hoping maybe Jim or somebody might have some ideas on how to fix the board or if there is a place to send it to for repair.
Thanks, Steve

[ccawgc]

Get the service manual from Hypertherm. Go the their web site and the down load area.
enter manual in the first box then go down and select the 380 from the drop down menu.
Click on the link below and select the service manual.
To make sure the pc board is bad. find the diagram in the manual that has voltages shown on it. Make sure the pcb has all it's input power supplies and control signals.
See if there is any output voltage. Be very careful measuring these voltages, some are dangerously high. we don't like to loose board members.
If Pc board bad its repair or replace.
You can try York, gem, industrial electronics, industrial south or inovat. Look them up on the web and call them to see if they can repair your pcb.
It may cost 50% to 75% the cost of new.

[weldersales]

If you send your board here, we will run it in known good machine at no charge to determine if it is the problem. If bad, we can exchange, repair, or replace. weldersales

[jimcolt]

I just noticed the post....If you feel comfortable troubleshooting high voltage circuitry...the tech service manual may help as CCAWG has suggested.....if not, you can't beat the offer from weldersales!

I find....in the majority of cases where there is no noticable board damage (burned sections) that the problem is just a loose or corroded connection. Unplug all connectors, clean the contacts, replug them. Inspect everything very carefully.

Keep us posted.

Jim Colt

[steve w]

Thanks ccawgc, weldersales, jimcolt for the help. I will take weldersales up on the offer if I can't find a problem. .The Hypertherm Tech did a excellent job of walking me thru all the checks he could on the phone. I did pull the board yeasterday and can't see any burnt parts, but we did maybe find a bad capaciter on the board # C 8 and it might be the problem. It doesn't ohm out right. It has I think RC 22v stamped on it. I don't know were to get one yet. I will try this week end to just take a better look at it and maybe clean all the terminals up and reinstall it before I do anything just see if that might fix it. If not i'll just have to send it up the road to big D. and let weldersales take alook at it.
Thanks for the help. Steve

[steve w]

I found the problem. It ended up being the rectifier. Not real sure what happened to the old one. I ordered a new one from millers4less. And installed it. I still couldn't get a good connection on one leg so I run a jumper off the leg to the other side and connected it to the terminal and it works great. I took the board back out so I could show what I did. I am going to fix it better but this helped me diagonose the problem. Miller helped with the getting me the part number so I could order the right one. $20.00 in all to fix. Thanks to Hypertherm and Miller and everyone for all thier help. It will be as good as new when I get fixed.
Thanks, Steve

[CNCdad]

Steve, do you remember who you talked to? I'm having problems with mine and they would not help me troubleshoot at all. They said to just buy another board.

[steve w]

CNCdad, I can't remember his name for the the life of me. That surprises me that who you talked too wouldn't help you trouble shoot the machine. Maybe call them back and get a different tech. Mine was over 5 years pass warrenty and he helped me check the gun and the voltages on the board and transformer. It all checked good but he told me the board must be bad. I took the board out and took it to work for some of the guys who know about electronics to look at it and one of them saw on the back side of the rectifier that the solder was blown off one leg. The same one that I attached the temporary wire to in the picture to show what we did. I called Miller Electric because they built it or had it made and they were real helpful at finding the part number for me so I could order one. I ordered it from Miller4less.com Then a guy I know that works for Radio Shack helped me put the new rectifier in but we had to solder a 12 gage wire from the bottom left leg on back and put a lug on it and screwed it to L1 BLK terminal. The copper path is deeper in the board making it hard to get solder to it. Been using it for 6 months now and know problems.
I would suggest taking the board out and look at the back side of the rectifier. It has a large screw going thru it to the heat sink. If you notice any solder missing then I bet that your problem.
You can order one from MIller4less.com, part number 200820. It's a Integ bride 35 amp rectifier.
http://miller4less.com/advanced_search_result.php?keywords=200828&osCsid=79d0n7q6m3k82u9bvbjb2sb031&search.x=9&search.y=13
It cost like $9.00 plus shipping and handling was around $10.00 so about $19.00 in all. It took about 2 weeks to get it.
Good luck,and hope you can fix it, Steve
When I took the board out I put tape on the wires I unplugged a marked them with the numbers on the board just to be safe. I also took a couple of digital pictures of the board all connected before I started disconnecting anything

[CNCdad]

thanks Steve, my plasma is flashing the power light when i hit the trigger so it is a little different than the problem you had. I'll try calling tech support again and hopefully get another tech. thanks again.

[steve w]

CNCdad, have you tried setting it on the other voltage and using it? Also have you checked your voltage at the recepticle to make sure it is good? I believe my manuel says the system line voltage needs to be at least 115 volts or 230 volts.

[duaneb55]

From the Operator Manual Troubleshooting section:

3. The POWER ON LED is blinking.

3.1 Line voltage is either too low or too high.
The following table lists the operating range of the
Powermax380 power supply. Have an electrical
technician check incoming power.

Note: Input voltage should be within 20%
of the specified system line voltage.

From the referenced manual table, acceptable input voltage limits for the Powermax 380 (& earlier 350) are:
115V - 92 to 138
230V - 184 to 276

If you don't have the operator and service manuals for the unit you can go here and download the .pdf files for both.

https://www.hypertherm.com/Xnet/library/library.jsp?locale=en

Select:
Product Type - Powermax 380
Category - Manuals/Service Information
Sub Category - Operator Manual (OM) -or- Service Manual (SM)

and go thru the pull-downs to get to the .pdf file.