Hi All,
I suspect my spindle drive problems are caused by a faulty power transistor module on the spindle drive.

Machine trips out OC when accelerated quickly in forward direction. Reverse runs fine though (99% of the time, but it has also tripped out before)

The power modules have the following specs and each package seems to contain duel darlington pairs:

EVL 31-055, 100A 550V ( 3 of)
EVM 31-050, 150A ( 3 of)

How can i test these with basic measuring eqpmnt (multimeter)
Can you still get replacements for these? and if not does anybody know of a suitable equivalent?

Drive is a Fuji Frenic V5000 Made in 1985