Chicago Electric mono mig 140

[bud]

Hay Guys
I need some help I have a Harbor Freight monomig 140 I purchest about 1991 and now it is broken I need a new power S/W and control pc board, it looks like this, if anyone can tell me where i might find them. Harbor Freight no longer carry them. oh ya a manual and wiring diagram Harbor Freight said thet did not have it as well.

Any Help at all would be great..

 

[shenion]

I doubt you will find anything for something 25 years old and sold by HF. Even new, parts were near impossible to find.

I'd look at a new MIG or a good used one. Last time I was at HF they had a pallet of the later models for $99; too bad you missed it.

 

[bud]

ya thanks
The Folks at Harbor Freight at first didnt know what I was Talking about he
said it sounds like it may have come from some place else, But I sent them a picture of it
and he said they would get back to me in 72 hours. I'm not to sure about that.
Anyhow I did fine some of the chips for the Board but if I don't find the S/W I may haft to
rewire with 3 s/w. one for power and the other 2 for hi low . so i'll keep on chuging along.
Thanks

 

[shenion]

The board is not that complicated. Should be easy to fix and draw a schematic. The transformers are the most common failure (primary wires corrode off.)

If you get a 5-6 position 2-pole rotary switch it should work. You should be able to figure out the transformer wires. It may need a separate on/off switch.

 

[bud]

yes I think I can get that, I am not sure about the blue box (relay)on the board It has 4 solder pins thru the board, I could read with a ohms meter across 2 pins but nothing on the other 2 I think it is the contack on the relay side and they are open, but I'm only reading 5.4 volts on the coil side of the relay and when I keyed the torch trigger it drops to zero on both sides of the coil, but the relay will not engage. so I need to find out why I have only 5.4 vdc on the coil side of the relay. I am thinking I should have 24vdc on it and there is no voltage on the motor as well when keyed as a matter of fact I cant fine 24v any place on any terminals.

 

[shenion]

The blue box would be the transformer.

I guess you have bypassed the voltage switch to get power to the board?

 

[bud]

yes I hard wired it like the s/w was on.

 

[bud]

I don't know why I have got this drive to fix this old welder, lol well i am going to try again, I'll get on here when I get some news.

Bud

 

[bud]

Good news Harbor Freight sent a PDF. (1151)of the mono mig 140 manual, But no wireing digram. so im am hoping for that as my second request of them. so there is still hope. I did draw the wiring of the circuit board as best I could but some of the circuitry has been burned off the board, I had palnned to etch a new board but need the values of the new components and with the damage some are lost. so here is hoping for the board layout.