Chinese welder help, WSME200

[xl15]

Hello everyone. This is my first post and I'm from Sweden so I'm sorry if my writing isn't perfect

I've bought a second hand chinese ac/dc tig welder from a friend.
It doesn't work properly. I'm pretty good with electronics and think (or thought at least) that I can fix it.

First of all, I'm not sure what brand it is. It was originally bought from Rehmann group in Germany. It looks like a generic 200 A chinese tig.

One pcb is marked WSME200C2

The problem:
The welding current is stuck to 13A DC and 27A AC. Fan is on, no gas and no HF start.
I'm guessing the main pcb or the front panel pcb.
Any suggestions?

 

[voipio]

Have you got any history of this welder from the person it was bought from? Did they tell you it didn't work? If so it would be useful to get some information from them about the symptoms, or how it stopped working, as this can often be helpful when diagnosing problems. Just knowing if there was a bang and a flash, or if it went quietly can help point in the right direction. Circuit diagrams would help, but I'm not aware of any for this welder. The user manual contains some sort of schematic but has no detail of the main control board circuit, or any of the other PCBs for that matter. It does, however, show the interconnect wiring and there are some values for the supply voltages present on the board connectors which may be helpful. These are a.c. so there will be some sort of rectification and smoothing circuitry to test the workings of. It's quite likely the main PCB is divided up into functional blocks, each with its own a.c. power supply, but most if not all coming from the single multi-winding transformer T4. There are several LEDs on the main PCB. Which of these come on when the unit is powered up? The fan runs from the mains. Does the numerical display light up and appear to be bright or dim under room lighting? It is probably run from a common type of DVM chip so info on that can be sought and the relevant inputs and reference voltage checked. Is the mains power LED on and the overtemp LED off? There should be approximately 1-1.1V across the contacts for the trigger. Are there any bulging electrolytic capacitors, or obvious signs of stress in the circuitry? Do the main electrolytics for the inverter charge up to the expected voltage? Are the wires to the control potentiometers in good order?

These are just ideas, and not organised in any particular sequence, but may be helpful. Let the group know how you get on.

 

[xl15]

I bought it from a friend. He said it just was stuck like this one day when he turned it on. So I guess it went quietly. Worked perfectly before. He bought a new one and I got this cheap from him.
The display looks normal.
I'll have a look at the LEDs on the main board tonight.

 

[mfletch]

Looks like a Jasic brand ??

http://www.aliexpress.com/store/pro...ELDER-FL007-220V-240V-1/509409_507695496.html

 

[xl15]

Thanks mfletch! I havn't been able to find the maker.
As for the LEDs on the main board, two are lit (in the red circles). A red one called 1V16 and a green, 1V31.

 

[NIls Voss]

Hey,
I am a little late right now but:
I have exactly the same welder,
Did you managed to fix the problem?

Best regards Nils

 

[dj graham]

hi not sure where to write a post but have super 200P Welder I switch the machine on and all I get is 3 000on display tried every knob on the fron panel and the dial does not move,. Can you help please thanks graham

 

[hunger]

Hello guys, i've the same problem, is someone have reach to solve the problem ?

there is no voltage to the 2 potensiometers to choose the current

thanks

 

[Relic]

Utube diode yap..
He fixes welders..
Search for a repair on a unit like yours.
May be something of use.
Mixture of languages.
Can understand when he brings out the multimeter.

 

[eddie49]

Bonjour, and welcome !
There are earlier threads about the WSME 200 welder on this Forum, and you can get some general hints on troubleshooting by using the Search box for "inverter repair".
E.G.

WSME 200 Tig Fault No Power

My Tig has just stopped working . Can anyone advise please. The fan runs when I turn it on nothing else lights up . No display is in the Amps Readout . I’m wondering if the power supply has gone wrong . I can buy one on eBay I think . Just wondering if it might not this as the fan runs ? Some...

www.mig-welding.co.uk

 

[Relic]

Does your tig have a tourch switch isolation board?
HF and gas down stream of isolation board on Strata tigs.
Small relays on isolation board are 12v.
I think power supply was on large top board with IGBTS.
This went through display to isolation board.
May help or confuse.