ShopMaster 300 not working correctly

[cruizer]

Well, since it stick welds ok, and tig is rough, even when scratch starting, AC or DC, I'm going to go with operator error, or bad gas. Likely using a C-25 mix.

[RoGrrr]

Well, since it stick welds ok, and tig is rough, even when scratch starting, AC or DC, I'm going to go with operator error, or bad gas. Likely using a C-25 mix.

I had wondered about the gas too. I checked the cylinder but it is pure argon. I'm wondering if somehow the cylinder is contaminated. I have yet to try the wire feeder to see if that works with mixed gas but I was mainly interested in tig so I deferred on that trial.
As far as your operator error suggestion, I don't take offense to that but doubt it is a problem since the boss had problems with it and he's a good welder.
I would imagine that like a blind squirrel, I could have found at least one acorn (a good bead on SS) but I never got a good sounding arc and the puddle just would not form.

[mediaad]

Thanks!!!!!!!!!!!!!!!!!!!!!!!!!

[RoGrrr]

Thanks!!!!!!!!!!!!!!!!!!!!!!!!!

WTF ?!? ?!?

[cruizer]

I'm willing to bet you that its a mixed gas, I've got a bottle here that plainly states Argon, but its a c-25 mix.

[txpaul57]

Hi,
I was wondering if someone has ever had the issue I am having with my Shopmaster 300. I was welding on a Friday and all was good, came in Saturday and not welding. Was running S32P, so first thing i did was troubleshoot the wire feeder but could not find any issues. so I tried stick and no arc at all. So after looking in a few forms and seeing the main issue might the CR1 or PC1, I replaced CR1 with OEM part, still no fix. Pulled PC1 out and looked for blown components, burnt spots or cracked tracing and still not seeing any issue. Called local repair shop and they said to test PLG55 pin 5 for 10V, was 11.3. Then tested PLG51 pin 1 & 2 for 18V, was 19.4. If I had voltages at these points then more than likely PC1 issues. Also checked TP1 which had continuity.

So knowing I didn't need to spend 800.00 on new PC1, I located and checked out a company 3E Services in Tucker GA, highly recommended, that had repaired many of the Miller 155826 boards. Called and spoke to them and received estimate, sent in for repair. Received back with a list of components replaced.

Installed board this morning and still same issue. So I tested SR2 for the heck of it..... But do not know where to go from here. Is it possible for the repaired board to not really be repaired? Never know unless I replace with a new one, but if not PC1 then I spent 800.00 for nothing, plus the repair cost of board.

I have gone as far as I can here, any suggestions?

Paul

[cruizer]

Well go one step further and shoot us that serial#