[Paul G. Swartz]

I have a mid 80's Mori Seiki mill with a Fanuc 6MB. It recently developed an error indicated by the ER3 LED on the control panel. According to my manual, I referred to PC parameters 240-250. I found that PC parameter 250 bit 0 is a 1. This indicates a machine alarm indicated by the 10 LED's on the power board. The LED for "servo fuse" is lit, but I can't find any problems. All 3 axis, the spindle, and the tool changer operate normally, but the machine won't cycle with the ER3 LED on.

Can anyone tell me what triggers the "servo fuse" LED on the power board, and how to clear the alarm.

Thanks

[Paul G. Swartz]

Fixed - "alarm" fuse blew without the main fuse blowing. The alarm fuse is normally open and closes upon failure of the main fuse. Since the main fuse was OK, all axis operate manually. I suspect the alarm fuse developed a bad connection that was interpreted as a main fuse failure.