Miller 302 - 120/240 work -- NO weld power

[ronsii]

Wondering if it's worth fixing or is this going to be a board swap $$$
Don't have the machine here yet but will in a week or so.
All I know so far is it has power on the genset side but none for the welder side???

[12V71]

Wondering if it's worth fixing or is this going to be a board swap $$$
Don't have the machine here yet but will in a week or so.
All I know so far is it has power on the genset side but none for the welder side???

Never had one of mine do that. I can check the schematic I have tomorrow. But it does sound like a problem with the weld generator. Remember, they have separate generators for weld and power.

[ronsii]

Never had one of mine do that. I can check the schematic I have tomorrow. But it does sound like a problem with the weld generator. Remember, they have separate generators for weld and power.

Yes, I believe it's very similar to my 325 just lower ratings??? I should have it here sometime next week to work on. Also have a 250 coming in and a 225nt that just shuts down when you try to strike... at least that's what I been told

Now I have to find time to troubleshoot these.... I *might* have to stay away from the pol thread more

[duaneb55]

IF it turns out to be a board problem, the main control board is a triple layered type with circuit traces sandwiched in between the layers. This makes this board "non-repairable" by most repair shops. I have had one repaired by a local former satellite technician years ago and it did take him two tries to nail it.

[12V71]

IIRC, the 302 weld output is direct to the studs, It may have an excitation issue, board etc. Also I remember a 5 amp fuse just behind the engine on the left side looking from the control end that powers up the board and excitation.

The 325 is a whole different animal, if I'm thinking right it has a single generator with dual output windings in the stator. and then goes through a board for the weld at idle feature.

Duane got there while I was hunting and pecking.

[ronsii]

IF it turns out to be a board problem, the main control board is a triple layered type with circuit traces sandwiched in between the layers. This makes this board "non-repairable" by most repair shops. I have had one repaired by a local former satellite technician years ago and it did take him two tries to nail it.

Uggghh, yeah I hate working on multilayer boards... some can be a real pain to get components off without killing the thruhole


@12v , thanks for the info I don't know why I was thinking the 302 was same as 325... thought I read it somewhere??? oh well... should be an adventure