Millermatic 250 Quit on me...Help!

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Hello all, I just got off a 7 month pump to afghanistan, and I can't even recall if I've posted on this board before. I signed up just before I left, and that's when my Millermatic 250 quit on me too. don't mean to start off by begging for help, but I sure could use some.I bought the thing used, and it worked fine for around 2 months. I was using it for maybe an hour total each weekend. I was in the middle of welding some 1/4 inch plate for a new seat mount in my Jeep, and it just stopped feeding wire and gas. The power light stays on, and I can hear the electricity buzzing, but when I pull the trigger, no gas, wore, or current.Fast forward to now I just got back and bought a new m-25 gun for it because the old one was wrecked anyhow. Still doesnt work. I was aware that the M-25 may not have been the problem, but I really needed to replace the old one anyways. I'm running out of options and money here and i was hoping you guys could point me in the right direction on what to look at first before I send it off to a repair center. I'm starting to think maybe something on the motherboard is fried. I've looked for loose connection, and havent found any. I'm pretty new to welding, and new to the forum as well so I appreciate any help you can offer.thanks again.
Reply:bump.
Reply:I have a MM-200 but don't know your machine. I assume it has some circuit breakers like mine does, and that you've checked them. Do you have a manual with the circuit diagram specific for your machine? If not, go to this  Miller Site,  enter your model and serial number, and download a copy.Once you have that, you should be able to use a voltmeter to check the control circuit from the gun, then the drive motor and so forth to determine where it doesn't have power it should.Perhaps someone else here has a better idea of what the problem likely is, but this should be a good start and you may find the problem easily. May just be a bad relay or connection.
Reply:Thanks for the suggestion. i have the manula and a good voltemeter. I dont have much experience with a voltemeter, but I understand that it's a pretty simple process. I'll give that a shot and see if I cant narrow the problem down. thanks again.
Reply:Welcome home  and welcome back. A machine SN would be helpful in identifying the right manual/schematic to be on the same "page".  Also, is it a straight up 250 or a 250MP or 250X?If it's a straight up 250 and in the absence of a SN, looking at the latest revision "N" manual diagram as a reference, I would check:1) PLG1/PLG2 from the main transformer that supplies 24VAC power to the board.  Check the plug terminals for corrosion and for the required 24VAC between terminals 1/3 & 7 (pilot light on panel face should be on) and 4 & 8.2) Check plug and all terminals in input harness plug PLG5 at PC1 Control Board receptacle RC4 paying particular attention to terminals 2, 6, 9 & 11.3) Check plug and all terminals in out harness plug PLG6 at PC1 Control Board receptacle RC6.4) Of course, check all harness plugs and wire connection points for loose/corroded terminals and if all checks out OK you may be looking at a control board problem.MM200 w/Spoolmatic 1Syncrowave 180SDBobcat 225G Plus - LP/NGMUTT Suitcase WirefeederWC-1S/Spoolmatic 1HF-251D-1PakMaster 100XL '68 Red Face Code #6633 projectStar Jet 21-110Save Second Base!
Reply:Wow,  thanks you for the very descriptive post Duane.My Serial number is: KF904251STOCK NUMBER: 903291Please let me know if these numbers change anything about the advice above, if you'd be so kind.I'm about to take the kids to the zoo, but I'll check those terminals later tonight and post back with my results. Thanks again.