Plasma Cutter

[OverkillYJ]

I have a broken Plasma cutter, and I only know the basics about how these things work. It is my father in laws. I am a field tech for technology so everyone gives me their broken stuff to fix. I weld a bit, but I have never repaired one of these. Apparently it does not turn on. I have a compressor and 220 line I can test it with. What should I be looking for? I probably wont get into it until early next week, maybe this Sunday if I am lucky though. Are these things dangerous to work on? Do they hold a charge or anything I should be worried about? I know it cuts up to 1/2", but he said he couldn't get it to cleanly cut 1/8" before it crapped out. He got it on EBay for $120. What you see in these pics is all that is on the machine. No labels with specific info or anything.

Any help you guys could offer would be great. I am out of what I normally troubleshoot with this one and hope someone on here has experience fixing these things. I am sure it can be done. Whether it is worth the money is a different story.

 

[toomanytoyzz]

It sounds like the circuit board crapped out. I'm no expert, but I know that it's going to be expensive to fix. It's an Asian brand, and they tend to have terrible customer service. If it was me, I would cut my losses (which doesn't look like you really have any) and look for an American made unit. Hypotherms and Thermal Dynamics are basically the Miller and Lincoln of plasma cutters. Also make sure you get one that requires an external air source. The units with built in compressors **** IMO.

Also try calling this guy at 302-690-6995 if you want to get yours repaired. He lives in Clayton, DE but is very knowledgeable about the Asian units. About an hour and twenty minute ride from center city. He buys broken 220V Harbor Freight units that were returned for pretty much nothing, and gets them running as good as new. I think his name is George. He is on weldingweb.com. Not sure of his username on the site, but search his number. He is a good guy.

Edit: Here's the link to his shop. http://www.georgesplasmacuttershop.com/

 

[RedneckWelder]

Stuff like capacitors and such can of course still harm you. Generally though I don't think there's a whole lot of stuff outside of maybe the power supply portion that could cause you a whole lot of grief. Could be wrong, though...

Generally these units are non-serviceable. Poor quality and non-existant manufacter support. There is a reason your father got it for $120 while a quality plasma is going to be several hundred to a couple thousand dollars...

You might be able to find a damaged component on a board and replace it if you're good at soldering/unsoldering and electrical troubleshooting...you'll probably have to order the parts from an electronic parts seller like Mouser.

The guy toomanytoyzz is talking about is probably going to be one of the more knowledgable people about these things. I've heard he does very good work and knows a hell of a lot about the HF units.

 

[zkling]

I'd check over all the basics first. Make sure you have good incoming power to the board. Check contacts, check the switch on the torch, good ground connection, good dry air, power switch. Basic things like that.

Beyond that you are looking at board repair on a component level. Can it be dangerous? Yes, but on something like that UNPLUGGED, honestly you will do more harm to the board than you will yourself by shorting a cap or the like. Always start with the basics. Handle board by edges, sniff it (for burnt smell), look for bulging or leaking caps, fried resistors, trans, IGBT if applicable for that unit. They are not extremely complicated, but paying someone else to repair one is not economical. At the lest it will be a good learning experience for you. If you are lucky they will have a schematic taped inside for you.

 

[OverkillYJ]

I just hooked it all up. Nothing happens when I try to run it except the air comes out. No spark at all. Since the machine is putting out air I assume it is not the trigger. None of the caps look damaged and I see zero imperfections in anything.

I have a multimeter and am competent at troubleshooting electronics, but am out of my territory with this thing.

 

[OverkillYJ]

I found this. That little gap there sparks when you try to use the torch. I am assuming it is some type of fuse I have never seen before? Is there supposed to be a gap there? I would assume this is supposed to be solid. If it is what would I do to go about finding a replacement part?

 

[Dustball]

Yes, there is supposed to be a gap there. This will give you a general idea of what that gap is for- http://weldingweb.com/showthread.php?35536-Spark-Gap-Settings