WSE 200 ac/dc tig not working

[arther dailey]

Hi
I have been given a WSE 200 ac/dc tig as the guy losing his workshop , it was working in his previous place but as soon as he moved it ..plugged in shows red overheat light on. With covers off all looks clean and no obvious damage , power up both fans run, red light on and you hear a click, like a relay , no spark at all. the contact points look burnt but I have nt touched as I dont know the gap settings . Anything obvious I can look for? thanks

 

[voipio]

Check the continuity across the two thermal switches, last pic but one.

 

[arther dailey]

Check the continuity across the two thermal switches, last pic but one.

both read as O/C. hopefully this is wrong but surely that would be to simple

 

[voipio]

The thermal switches are wired in parallel, which suggests that open circuit is correct for a machine that isn't overheated. If they were wired in series, then they would have normally closed contacts.

 

[arther dailey]

The thermal switches are wired in parallel, which suggests that open circuit is correct for a machine that isn't overheated. If they were wired in series, then they would have normally closed contacts.

thanks

 

[cocker]

My little migatronic did the same , dropped it off to be fixed and it worked as soon as it was plugged in ?
They thought that as I live out in the sticks the supplied electric might have been a bit up and down .

 

[Jan-DIY]

The boards looking badly bend.
My mate collected one which breaks after transport because of some kind of that.

 

[Epace]

These two transistors have been replaced and the others may not be good either...

 

[arther dailey]

These two transistors have been replaced and the others may not be good either...
View attachment 398873

thanks, thought the were just the tails from the units clamped down? but there again I know more about women than electronics

 

[arther dailey]

The boards looking badly bend.
My mate collected one which breaks after transport because of some kind of that.

View attachment 398608

is that from one of my pics ? or your friends,thankyou

 

[arther dailey]

Right , got brother to check it out as I am not electronics minded , he soldered a few joints etc, but overheat light is still on, tried torch to see if any sparks, there werent , well that is untill I went to undo torch with power still on and got a tingle, so presuming earth isnt connected and it did nt trip the trip (brother is fully qualified tv eng)
So what does the fact that the outer socket of the torch was obviously live point to other than no earth connection? the one thing brother told me one board wasnt fixed in completly so some ones been in before which is never a good sign.

 

[MattF]

but there again I know more about women than electronics

Chuff all then?

 

[arther dailey]

Chuff all then?

same as any bloke I geuss

 

[eddie49]

I went to undo torch with power still on and got a tingle
So what does the fact that the outer socket of the torch was obviously live point to other than no earth connection?

"Getting a tingle" implies leakage of AC mains, and, as you said, no chassis earth. Sometimes on imported machines the mains cable has only 2 cores, or the earth wire is cut flush after the strain relief grommet, or a fly lead is not attached to the casing. The effect could also possibly be due to HF start active?
The AC mains feed should only get as far as the full-wave bridge rectifier across the input supply, after that all power is derived from the 325v DC bus. Both sides of the welding output power connections should be fully-floating, with nothing in common with AC mains earth or the welder chassis. There may be a noise filter with a leaky capacitor, or possibly even a Power Factor Correction circuit - but I doubt that this machine has PFC.
The "click" of the soft-start relay after power-up implies that a low-voltage power supply and some of the control logic is working. Probably there are no gate signals triggering the MOSFETs/IGBTs to run the inverter.

 

[arther dailey]

I need to have another look under the cover ! it would be very usefull if I can get it working as only do ally every now and then , so to spend lots of dosh on something that gathers dust most of the year makes little sence. migs n steel all good and often get used , would nt mind one of those shermans but wasnt cashed up at that time although they were at sensible monies.