Miller Aerowave HIGH TEMPERATURE false alarm

"Ignoramus28365" wrote in message news: snipped-for-privacy@giganews.com...

Does the continuity extend back to the controller board?

I'd un- and re-plug all the connectors first.

-jsw

If it uses a bunch of normally-closed Klixon snap-disk switches as overtemp sensors, they are probably all wired into a supervised loop (alarm if zero current), like a burglar alarm, so a bad connection or cracked wire anywhere will be reported as over temperature.

Joe Gwinn

Possible wires broken inside the insulation in the wiring to the temperature sensor switches?

Possible broken connection in the printed circuit board where the temperature sensor switch wiring connects -- or where it carries the signal.

Possible bad input on a logic chip which is sensing the switches. (Are the three switches connected in series from a reference voltage (possibly ground), through all three switches, and then to logic via a trace in the board? Or is each switch separately wired to the board?

Is it all one big logic bump under epoxy, or are there individual chips scattered around the board? This may determine whether it is easier to replace the board or to replace chips on the board. If individual logic chips -- with part numbers -- you can probably check for the signals to the chips, and out of them, and identify a failed chip, if there is one.

For that matter -- look at the board with magnification for "cold solder" joints. reflow any questionable ones.

Do you have a schematic of the board? If not -- can you get one?

Good Luck, DoN.

"Ignoramus28365" wrote in message news: snipped-for-privacy@giganews.com...

-jsw

Thats a good thought, but not the case. There is continuity in that circuit. Additionally when I short the leads going to it, it does not help.

O.K. The overtemp switches are TP1, TP2, and TP3, so the first thing is to check continuity between RC8-1 and RC82 (wire 62 and 61). If that shows low resistance (e.g. below say 5 Ohms), then it is time to trace the P.C. board, starting at the RC8-1 and RC8-2 terminals.

Of course -- no schematic of the boards. Maybe you can find somewhere where someone traced the boards. If not -- you'll have to do it.

Good Luck, DoN.

replying to Ignoramus28365, Daniel J Vaughan wrote: Hi, I realize this is an old post, but I have the same welder and am having the same issue. Did you ever resolve the problem with your welder? I checked RC8 1 & 2 (specifically I disconnected the plug and checked continuity between wires 61 & 62 inside the plug) I do have continuity there, so I'm suspecting the PC board. Thank you for your time.

-Dan