Big Blue problems...question for the CST folks out there.

[Mickey(not so fine)]

Please do keep me posted! I understand the time sink involved with diagnosing intermittent problems...drives me nuts!

Mickey

[Mickey(not so fine)]

Well ****, I'm quickly running out of ideas! I had really hoped someone else with more experience on these machines would have chimed in by now...for yourself and my own peace of mind! I'll keep looking and at this point, I'll throw anything out there and hopefully something will stick!
...

[Mickey(not so fine)]

Alrighty, might have something...the Mitsubishi motors have a magnet sensor by the flywheel. It threads in on the shroud and sits right over the teeth on the flywheel. It can come out of adjustment or have a build up of debris that could cause erratic rpms or a no start scenario. The sensor also...

[Mickey(not so fine)]

I would think that if the windings were the culprit, you'd see some additional issues with your welds and such.

When I described what was going on to my guy, he immediately said fuel pump. I dunno 'bout that though with the intermittent symptoms. He went on at length about the pump...

[Mickey(not so fine)]

I've run across intermittent issues on the electric side of things the same as on mechanical or fuel side of things. Not as frequently mind, but still fairly regular...often enough to not dismiss anyways.

My experience with diesel is limited as of now, but I've encountered lots of issues...

[Mickey(not so fine)]

I got the impression that wet stacking was unburned fuel building up, but I truly don't know much about it. I recall it being mentioned with new machines having to be broken in with a load bank, but that was all. My Miller training was 5+ years ago and my memory is dodgy at best. It didn't even occur...

[Mickey(not so fine)]

I'm wondering if you're having a problem with "wet stacking" that's causing all that. I've only heard about it, never actually saw it for myself, just mentioned in passing. Anyways, while going through the manual for the 400 I'm working on, I ran across something that says it risks wet stacking...

[Mickey(not so fine)]

So, way off on the symptoms...that's what happens when the purchasing agent of a power plant gives you the information rather than the poor bugger that uses the machine. When I talked to the fella the uses it, he said "under 40a it won't scratch start tig and over 40a it gets real hot". ...

[Mickey(not so fine)]

Ouch, no good at all. A 400 was dropped off for repair the other day with what the customer is describing as a similar problem. I'll hopefully be into it this afternoon. If it's doing likewise, I'll keep you updated on what I find.

Mickey

[Mickey(not so fine)]

Those intermittent problems are bloody nightmares! A couple months ago, I had a Vantage 500 come in with a similar issue...not the same mind, but similar. It ultimately was his fuel. He'd gotten diesel algae in his tank and his filters were plugged up enough that it would bog down and come close...

[Mickey(not so fine)]

Thankya jjohn76! That was bugging me something fierce! That was the only one I've gotten ahold of to tinker with that was like that so far. I've been able to play with a couple POWCON's over the years, but never had the petticoats up to get a peek of how they're assembled.

Glad you got...

[Mickey(not so fine)]

I seem to remember one of the states to the west...Nebraska maybe...had a governor in the last year or two that took up the fight for right to repair and won. If memory serves, it was aimed mostly at John Deere.

Board level troubleshooting is a bear! Especially with a lot of the boards...

[Mickey(not so fine)]

Ya, that's been my experience with Miller on the Big Blue's...its always the board. Once I get the board installed, still have the same issue and then its the power modules, hall device, etc. I can imagine how irritating it is...I hate having tools that just sit and don't make any money. Its even...

[Mickey(not so fine)]

So, looking at the diagram, I believe I was mistaken on that. It looks like the 212 is not the machine I recall...I wish I could remember what machine that was that I was thinking about. Anyways, your fan is going to be separate and controlled by the board and a thermistor. If there's a problem with...

[Mickey(not so fine)]

I couldn't find my notes from that particular repair, but if you have power going into it, there should be power coming out. You may still be getting some voltage to the board so it will power up a bit but not really do much else. If you're not very comfortable with electric, I'd suggest taking it...

[Mickey(not so fine)]

Aaron,
If I recall correctly, the fan "motor" is also part of the power supply to the board on the MM212. If its the same, awhile back I had a customer that wanted a board and once he got it, the machine still wouldn't power up correctly. He brought it in finally and there was a failure...

[Mickey(not so fine)]

Wow, another issue to add to the list as I've not seen that yet. So far what I've encountered keeps pointing at PC1 and once I replace that, its usually followed by replacing the power modules and the hall device. That get's pretty expensive pretty quick. I did read your other post and my first inclination...

[Mickey(not so fine)]

I suppose that could be a possibility. If it is, it sure would be handy if they'd let their CST guys in on the secret.

Mickey

[Mickey(not so fine)]

G'morning all,
Are there any folks out there having issues with the Big Blue welders. It seems that every single one I've encountered in the last couple months has had some really squirrelly issues that have been a massive problem to diagnose and the diagnosis is usually incomplete or incorrect...