Miller MIG stopped working - ideas where to look first?

[beertestr]

I seem to be having a hard time keeping my MIG and TIG running these days. My TIG was down after I dropped a piece of exhaust pipe perfectly on the hoses, and sliced 2 of the 3 hoses completely in half. That's fixed now, but when I went to use the MIG last week, the trigger didn't work. I checked the connection from the gun to the welder, looked good. I even hooked up the spare gun I had, and it did not work either. Power comes on, fan comes on, just no response from the trigger so the spool does not advance. It's something internal, and I have not opened up the case to look (no time). Since I am bored as hell and sitting in a meeting, I'd thought I'd ask to see if there are any common places to look while troubleshooting..

Welder is a 15+ year old Millermatic 150, 220V unit.

Thanks..

 

[igotaneed4speed]

There is probably a fuse for the trigger circuit or relay that's gave up the ghost. Did they give you a wiring print on the machine when you bought it?

 

[WhiteHawk]

Motor for the spool? Any way you could test that?

-Geoff

 

[igotaneed4speed]

If you can trace the spool trigger wires back to the machine you can ohm the switch out, verifying the switch and wires all the way back to the relay. If that checks good I'd check the relay. Most relays have a printed circuit on them if not pull a part number off it and google search it, you should find a relay diagram and pin identification sheet pretty easy. Once you have that you will know what the power rating i, where to set the DVOM and what pins to pin out checking for ground, power and activation.

If the relay checks good and has power then I'd check for power to the motor with the trigger pulled on the gun but chances of this not having power are very slim. I'm assuming this welder uses gas, when you pull the trigger the relay should control both so if they don't both work then i doubt the motor being bad. Most likely power supply to the relay or the relay itself is the issue as it should supply the activation to both the gas solenoid and wire motor.

 

[beertestr]

OK, I'll check the relay, hopefully tonight..

As for documentation, nothing. I got this thing used from Re-tool back in 1999 or so. Scored it for $350 back in the day. It's been a great welder. Any time I see it's sucking ass on penetration, I think of getting a new welder... Then my dumbass remembers to change the tip.... runs great again. I feel like the guy that wants to trade in his truck when it needs an oil change..

 

[OnyxSSS]

first time my mig acted up and would not push wire when I pulled the trigger...it ended up being out of wire!
gl

 

[DennisH]

http://www.millerwelds.com/om/o1310f_mil.pdf

Dennis

 

[beertestr]

So after several looong minutes of looking for the root-cause (which means about 5 seconds after i took the cover off) if found this...


Looks like these internal wires are zip-tied to the power leads and apparently the power leads have been tugged out a bit... a little tugging back and adjusting..... works like new again... now if my carb issues on my tractor only took this long to fix..... thanks to all for posting..

Sent from my DROID BIONIC using Tapatalk 2

 

[igotaneed4speed]

So after several looong minutes of looking for the root-cause (which means about 5 seconds after i took the cover off) if found this...
View attachment 64549

Looks like these internal wires are zip-tied to the power leads and apparently the power leads have been tugged out a bit... a little tugging back and adjusting..... works like new again... now if my carb issues on my tractor only took this long to fix..... thanks to all for posting..

Sent from my DROID BIONIC using Tapatalk 2

haha gotta love easy fixes! Blow that poor thing out before ya put the cover back on, it'll last longer the dust holds in heat on electronics.