I have an old Mori SL-2 with a 3T Fanuc control. Powered it up this morning and found that the spindle would only go about 200rpm during warm-up. We had this problem before and it was a fuse. No such luck this time. Can anybody point me in a direction for diagnosis?

10/20 found the problem yet? need more info to help. Alarms? G50 cap on speed? noises?

We found a momentary voltage drop off on pin #1 on the drive board, but then it seemed to recover. Machine is now running. We have a meter on it to let us know if there is another voltage drop. There were no alarms probably due to the signal getting through and spindle start confirmed even though it didn't get to speed commanded. Had to find a break in the line when it is so intermittent. We'll just have to wait until it drops again.