Lincoln Welder Board Diagnosis and Repair Help Needed

[U1138]

Here is the situation:
1. I have a Lincoln Electric 210 MP that is approximately 5 years old
2. The other day it tripped a breaker which is not uncommon since I've been running it on 120 not 240. Usually I just reset the breaker and turn the machine back on.
3. Reset the breaker, turned the machine on and maybe 5 seconds into the boot process it tripped the breaker again (not welding, just booting so very low power)
4. Tried different circuit, same result, the breaker was tripped about 5 seconds into the boot process
5. Detached everything (MIG gun, extension cord, etc...) from the machine and tried again, but the result was the same.

There is a authorized service shop for Lincoln nearby which could be convenient, but since I thought it was just going to be a circuit board swap I thought I might do it myself. At least that's what I thought until I found out the board was $700 (keep in mind this was a $1000 machine when I bought it). So, at this point I thought it was worth it for me to try a component level repair on the board. I was hoping that I'd open the machine and find a blown out component with scorch marks next to it, but that did not happen. The only thing I see even slightly discolored is the transformer.

I'd be interested in hearing suggestions on how I might approach diagnosis and repair (mind you I know little more than Ohm's Law when it comes to electronics even though the subject interests me)

[tpowell1830]

Hi U1138, welcome to the forum.

Will be difficult for anyone to troubleshoot your welder just from pictures. I do not see anything obvious. The question that I have is, have you checked the current on the line when you turn on the welder? If you continuously trip breakers, sometimes they get weak or bad. Could you simply have a bad breaker?

If you can't catch the incoming current reading on your welder, try the welder on a different outlet that is controlled by a different breaker. I recommend that you get the current reading if possible.

Maybe someone with this welder that has experienced a similar problem can give you some insight.

Hope this helps...

EDIT: Oops, didn't see number 4, floobydust has good advice.

[floobydust]

Maybe don't keep retrying things, you can do more damage. The welder board likely has an inrush-limiter which operates for the first five seconds of power up. Usually a relay that switches out after the main DC bus capacitors are charged up, or it could be a PFC section for stage-2. Hard to tell without better pictures of the board.

I would test the power semiconductors on the heatsink for shorts. Something is shorted well enough to blow the breaker.

[perieanuo]

hi,
suposing your breaker is not de-calibrated (yes, it can happen after some cycles of breaker activayion, his capacity goes down), just test the power elements on your pcb's, like power transistors, diodes, bridge etc, why not the big capacitors on input side.
tell us the result (I guess the device tests itself generating some current pulse even when it 'boots')
regards,
pierre

[U1138]

Thanks, folks. I'll make a few tests over the weekend and post the results.

I was trying to pull the board out and came across this fastener, have any of you seen this before? It's almost like some weird rounded off torx.

[akimpowerscr]

....
I'd be interested in hearing suggestions on how I might approach diagnosis and repair (mind you I know little more than Ohm's Law when it comes to electronics even though the subject interests me)

Even electronics professionals often no longer do component level repairs.
They just change the boards.
Repairing a board at the component level requires a test bench specially designed for this purpose, a stock of original spare parts and complete service documentation.

Trying to repair a board in a power equipment is very risky because these boards are connected to power circuits, hence the risk of electrocution and also destroying other components, expensive and difficult to find.

The best you can do is find a competent technician near you and ask for his help.

Remote troubleshooting on the basis of information obtained from a forum is already difficult when you are competent and have the diagrams, so, when you do not know anything about it and you have no documentation, it is is simply impossible.

Obviously, you can always be very lucky and come across a visible and obvious flaw .....

[U1138]

Even electronics professionals often no longer do component level repairs.
They just change the boards.
Repairing a board at the component level requires a test bench specially designed for this purpose, a stock of original spare parts and complete service documentation.

Trying to repair a board in a power equipment is very risky because these boards are connected to power circuits, hence the risk of electrocution and also destroying other components, expensive and difficult to find.

The best you can do is find a competent technician near you and ask for his help.

Remote troubleshooting on the basis of information obtained from a forum is already difficult when you are competent and have the diagrams, so, when you do not know anything about it and you have no documentation, it is is simply impossible.

Obviously, you can always be very lucky and come across a visible and obvious flaw

Challenge accepted, hold my beer 😁

[MadTux]

I would disconnect the inverter stage and see if the fuse still blows.
If so, something wrong in the inverter, like shorted MOSFETs or diodes.
Else problem in controller electronics, HF start or a short elsewhere in the electronics.

[U1138]

So, I figured I'd take a shot at checking the 7 transistors along the top of the board until I can figure out how to get the board out. These are [url href="https://datasheetspdf.com/pdf-file/805311/Infineon/K40H603/1"] K40H603[/url] and I used the pinout shown in one of the pictures below.

Using my multimeter set to measure Ohms I gathered the results for each transistor as shown in another of the attached pics ( B+ / C- means my positive lead on Base and negative lead on Collector, etc..). Am I doing something wrong? It appears as though some of these conduct in both directions which would mean either I misunderstood something or they are indeed fried and need to be replaced.

Thanks,

[Cuzican]

Once again I’ve stumbled across this forum while pondering others’ experiences with a problem I share. I finally decided to join in.
I’ve had a 210 for about 4 years
Warranty replaced the pcb in year 1. My failure mode was almost identical
Problem arose on the 110V 20A bkr with extension cord. Tried on another, like breaker, no extension cord. Tripped. Tried 220 pigtail 50A bkr. Tripped

Now, after 3 more years, and about 40 hrs of use, the failure mode has reoccurred.

If memory serves, both times I was attempting welds , who’s settings would require greater amps than the 110V should be used for.
I didn’t concern myself with the machine’s limits. I figured it would protect itself.
Not so sure now.

[Dataminer17]

Hello Electronic Friends, Have the same issue on this Lincoln Electric Multi-Process 210 (MP210) and was curious if the MOSFET component swap worked the OP's board fault? I just spent $50 on a broken MP210, plugged it in, it booted for 3-4 seconds, and then blew the break. Upon searching the inter-webs, this is a common PCB Board fault on these machines. Since I am only into the thing for $50 I was going to be placing an order for some Infineon K40H603 – Insulated Gate Bipolar Transistors and which OP has labeled within this picture with all of the numbers as 7-4, but it seems that 3,2 &1 are Vishay FEP30AP Dual Common Cathode Ultrafast Rectifiers.

If anybody has any thoughts on what components need swapping to make this board viable, please let this guy know... Thanks folk. Appreciate the information in this thread.

FYI- All of OP's pictures apply to my exact situation, so please see those for reference.

[ferrisd65]

Could be the IGBT. 

Check the temp on the Resistor ( see Picture)

https://youtu.be/uWhi2y-ThqA     Different machine but similar in theory.

[ferrisd65]

https://youtu.be/JDIOp8QbHWQ