I got the factory manual and gone thru most all tests. 98% sure it is the main controller card (transistor card in the book). Going thru the test procedure shown in the book for the CH1 gives exactly the revers of the correct voltages.
Where do I get one? The owner previously sent it out to a company called: " Flight Systems Industrial Products" or possibly "THV Parts" and as far as I can tell there was absolutely nothing done to it. After a return trip to said repair company at least we were able to determine that they had managed to break the lead off one transistor. Replacing it did not help.
I DID find earlier that fuse #12, supposed to be a 1 amp, had been replaced by a 30 amp one. That might explain why 2 traces on the card were smoked and replaced with external wires. (This all prior to my customer buying the machine.)
The only thing I have not tested is the little box that is called the contactor detecting circuit. Tests shown in the book requite building a small harness to test it off line.
Any one have one for sale?
TIA,
Al