Millermatic 135 Control PCB Schematic

[hemi-1]

Fixed! Welder is now operating normally with full voltage and wire speed controls working. Replaced electrolytic capacitor C24 and ran the unit for awhile simulating trigger on (welding). This is a friend's welder so after he actually tries welding with it I will report back with final outcome.

[Maviday]

Well does it weld good?

[samuil_mk]

It had the same problem like yours
Erratic wire feed
Now I wanted to try it but I'm afraid to connect the board as I'm not sure of which wire from the colored ones goes where on the board so I stopped there

[samuil_mk]

So please someone

[samuil_mk]

I changed bad tiristor, ( q5)

[samuil_mk]

Ok thanks everyone
I found some schematic on internet, Now my 135 welds perfect