Welding Tips and Tricks

Hi Guys,

Went to fire up my machine for a quick job yesterday, and noticed the overheat light turned on immediately. After some snooping around, I noticed two long cylindrical devices that Lincoln says are resistors (#5 and #6) on the parts list. One of them stayed barely above ambient, but the other one shot up to to near 200°C immediately.

Has anyone ran into something like this before? I'm handy enough, but no electrical guru. Is it as simple as replacing that resistor, or is this the effect of a different short/malfunction somewhere else inside the machine? I don't use the machine very often, but this is the first time in 10 years it's given me any problems. Worked just fine a couple weeks ago!

If anyone has any input/ideas, I appreciate it!

I don’t have a specific answer to you on the resistors, but, since you have access to the back of the machine, now is a good time to do a decent cleaning of it. Vacuum and/or blow out any grit and debris that might have accumulated. Make certain the machine has ample free-air space around it while running too.

Generally, I would think that resistor can be replaced. If you have access, there are repair shops that might be willing to give you solid advice and even point you to a source for parts replacement if you need.

Advan wrote: ↑Sun Sep 22, 2024 1:51 pm Is it as simple as replacing that resistor, or is this the effect of a different short/malfunction somewhere else inside the machine?

Generally, resistors get hot as a result of something else being wrong. Changing the resistor is unlikely to fix the problem.

As suggested, clean it out first and make sure nothing is loose and/or shorting. After that, I'd be looking for a circuit diagram.

Jack

Thanks guys. There really isn't anything obviously wrong inside the machine. I've obtained some schematics and enlisted the help of an electrical engineer at work to help diagnose. I'll update the thread if he comes up with anything.

Thanks!

post a pic of the schematics if you can.