Need help repairing Miller synchrowave 250

[coppermouse]

I just got a good deal on a Miller synchrowave 250.
It is about 18 years old. The problem with it is that when you push the foot pedal it turns on full blast and is not able to throttle with the foot pedal. Already checked it is not the pedal. Any help you be appreciated including where to get a service manual, schematic. Would like to fix on a budget and fix at the component level if possible. Thanks !

 

[OccupantRJ]

Google is your friend....

http://www.millerwelds.com/om/o353u_mil.pdf

 

[coppermouse]

Thank you but I also need a schematic for the circuit board PC1

 

[tdkkart]

Does the 250 allow doing scratch start with the pedal disconnected and adjusting with the front panel knob?? Can you adjust the max amperage with front knob??

Unfortunately, if it does it with another known good pedal it most likely the board, which may or may not be cheaply repairable at Miller or one of their service centers.

 

[madjack]

Had a problem very similar with my 350. Turned out to be an internal short in the pedal itself.

 

[sberry]

I was fortunate to have full schematic to a 300, had my tv repairman Bud fix the board. You might be able to find someone with drawing.

 

[coppermouse]

I am an electrical engineer and bought it from our company. It was checked by the repair shop and they said the pedal is good. They said it is PC1 board and it is expensive. I got the whole welder for $200. It strikes an arc but stays on full blast of what the main current knob is set at. If I must I can draw a schematic from the board backwards but it will take a ton of time. I am sure with an O scope and schematic I can fix it. If anyone has it or knows where to get it I would be greatly appreciate it.

 

[79firebird]

if it stays on full blast i would try looking at the main current knob first

 

[Tantara]

Make sure you have the toggle switch labeled remote tuned on to remote.

Brad

 

[coppermouse]

When I say stays on full blast I mean full blast of what the main current knob is set at there is not control within that. The remote switch is right. It has already been to the repair shop and they said PC1

 

[slicktoptt]

If there is someone that can help it is probably this guy.

"Cruizer" on Miller's forum. He repairs them and has a general wealth of knowledge.
http://www.millerwelds.com/resources/communities/mboard/member.php?u=6989

Good luck.

 

[coppermouse]

Thanks I will look him up