Welder Repair Help

[Machtsinn]

Hello @ all.
I hope, you guys can help me.
I have problem with my Chinese welding machine. I got it from Ebay. Unfortunately it wont's work.
No warranty, no return.
So, I have to repair it. I changed Relais, Trafo and resolded blown interconnection on this Board and replaced parts on another board(second image). Nevertheless no lightbow.
I found out, that if I push a trigger the Relais don't snap. So in my opinion it become no voltage.
Any Ideas?

Thanks in advance,

Konstantin

I would very thankful, if some one could upload wiring diagram.

 

[gearhead63]

I don't know what you replaced/repaired, but there is a blown transistor beside the 4-prong connector it's the third one from the top just to the right of the connector.
What make and model is this welder? Have you tried googling the part numbers from the PCB to find schematic or another board? It's beside the big connector on the left side, looks like 577-88916, don't know that I'm seeing all of it.

 

[shortbus=]

That same row of the board looks like it has a blown/overheated diode. Diode #1N4004