Miller XMT 300 troubleshooting

[Adam Mc Laughlin]

Hi Everyone

Trying to repair an XMT 300 that had belonged to an old family member.
This is not the unit that is auto-link, it is the 240 V edition.

When I first opened it I found that the LEM board had a burst electrolytic, so I got a replacement LEM board from Miller. Installed it and replaced the bad switch on the upper left hand side, middle row. That switch was crunchy so I ordered and installed a replacement one. Switch alone was $66 - for a switch!

Anyway, problem now is that while the unit turns on and powers up it does not strike an arc or indicate anything on the LED display -
anyone tackled this before? Any recommendations as to what to do next?

I took electronics certificate program at the local community college a few years back, I don't mind diving in but was hoping that all of you might have a suggestion as to where I should start.

Adam

[Aeronca41]

Welcome, Adam. I know nothing about your welder but there are those here who do. Hope you get an answer.

[H80N]

Hi Everyone

Trying to repair an XMT 300 that had belonged to an old family member.
This is not the unit that is auto-link, it is the 240 V edition.

When I first opened it I found that the LEM board had a burst electrolytic, so I got a replacement LEM board from Miller. Installed it and replaced the bad switch on the upper left hand side, middle row. That switch was crunchy so I ordered and installed a replacement one. Switch alone was $66 - for a switch!

Anyway, problem now is that while the unit turns on and powers up it does not strike an arc or indicate anything on the LED display -
anyone tackled this before? Any recommendations as to what to do next?

I took electronics certificate program at the local community college a few years back, I don't mind diving in but was hoping that all of you might have a suggestion as to where I should start.

Adam

First PLS post your serial number ... that way the correct schematics and docs can be looked up....

If I recall some old threads correctly... that unit has some unique troubleshooting challenges....and that Cruizer has lot of experience with them...

Hope he checks in on this one............

[cruizer]

These are dangerous machines to both troubleshoot and successfully repair. I still stand back when I turn it on. I would stop throwing parts at it. Just not worth the time, effort and substantial $$. For the limited return