Please Help Miller 875

[Kitt1993]

Hello,


I'm Bryan and new to this forum. I've been in the metal fabrication for many years and finally was able to purchase a DOA Miller 875 Plasma Cutter off Ebay. I realize that its probably better to purchase a new one or one that works, but I like the challenge of diagnosing and repairing my own unit. That being said, according to the listing, its a 2016 Model and isn't turning on. Well It just arrived today and sure enough, theres no pulse. I was wondering if there is a diagnostic procedure on what boards to test in what order. I called Miller and they weren't very helpful and suggested that I throw away the unit, again I realize that its not worth repairing, but I want the experience and the opportunity to get to know this unit in and out.

Appreciate any support.


Bryan

[adbuch]

Hi Brian,
Here is the factory manual which contains troubleshooting guides as well as electrical circuit diagrams/schematics. Let us know how you make out with it, and if you have any questions about the circuit diagrams.
David

o234163a_mil.pdf

[ScottRa]

Wow...4 years old and they don’t want to support it? I have a lot older syncrowave 200 welder that’s in great shape. I’d hate to have to replace it just because I couldn’t get a part for it.
Someone was troubleshooting a plasma here a while back that was obvious because it had badly burned parts of a board.
If you haven’t already a good inspection for board or part damage might give some clues to where the problem is.

Scott

[Kitt1993]

Hi Brian,
Here is the factory manual which contains troubleshooting guides as well as electrical circuit diagrams/schematics. Let us know how you make out with it, and if you have any questions about the circuit diagrams.
David

o234163a_mil.pdf

Hi David,

Yea, I have the manual , but it doesn't tell you how to diagnose the internal parts. I'm going to take it apart this weekend and see what I can find out. Wish I had a schematic.

Bryan

[Kitt1993]

Wow...4 years old and they don’t want to support it? I have a lot older syncrowave 200 welder that’s in great shape. I’d hate to have to replace it just because I couldn’t get a part for it.
Someone was troubleshooting a plasma here a while back that was obvious because it had badly burned parts of a board.
If you haven’t already a good inspection for board or part damage might give some clues to where the problem is.

Scott

Hi Scott,

Yup, the warranty is only for 3 years so it expired summer of 2019. Like I said to David, I will take it apart this weekend and see whats going on. Any chance you might be able to find that thread you spoke of?

Bryan

[ScottRa]

Here it is...it was a Powermax 45.
https://www.plasmaspider.com/viewtopic.php?f=60&t=30653
Scott

[adbuch]

Yes - inspecting the circuit boards for damaged or burned spots could provide some clues to help you locate the problem area.
David

[Kitt1993]

Thank you all. Will keep you posted on what I find.


Bryan

[adbuch]

Good luck Bryan! Hope you get it fixed.
David