Snap on YA212a welder diag help!

[southern_boy79rs]

So I have a Snap on YA212a welder that came with my current house/shop. Got it out to start checking over for proper operation etc. Plug up, flip switch, fan comes on, power light comes on, wire feeds, but no arc. no voltage on gauge either. I’m a mechanic by trade so I’m not sure where to start with seeing what’s wrong with this machine. If it were not free I might not fool with it but it might be a simple repair and I can use for a while. Included is the inside and the main wiring diagram. Can anyone help me out where to start?

 

[RTM]

Without knowing anything about welders, I would start by taking your wiring diagram, and marking what works and doesn’t. This would tell where the gap is.

One thing I would check first, with unit unplugged, is the NC Thermal Switch having continuity. It’s a high temp safety switch. Since the wire feed works, and it’s on the right side of that circuit, and the left side controls power to the high voltage side, and the NC (normally closed) Thermal Switch is the big difference between them, I’d guess there.

If that’s OK, the Contactor Coil / Relay contacts after the fan circuit would be my next target.

 

[scooby074]

k

 

[southern_boy79rs]

To whoever is curious got to “repaired” had to get my multi meter from work so I could use on AC voltage. I usually keep cheap one around the home shop for DC and continuity etc. Long story shirt found the contacter closing but no voltage on one leg out and found a stink bug stuck in it. So now I have a working antique of a welder but it was priced at free so works for me.

 

[txvwnut]

Glad it was an easy fix. I have one of those and it’s been flawless for the nearly 30 years I’ve owned it. It doesn’t get much use nowadays as I do mostly TIG but when it’s needed it always fires up and welds without any issues.