[bitson555]

I have a colchester cnc lathe fitted with a Fanuc 20 T control (1996)
I am trying to eliminate a random 401 vrdy axis error on the Fanuc control.

I have noticed on the Fanuc Alpha Power supply when I removed it to check it internally that there is no large, 100 amp fuse fitted in the space at the top of the power supply,
is this normal ?
The machine seems to work ok without a fuse fitted but is this standard?
The Spindle drive and servo amplifier both have this 100 amp fuse fitted, so why not in the power supply?

I have removed the servo amplifier to check it out as well and have noticed that there is a space for a small battery pack but there is no battery fitted,
Do I need to install a battery or will the control work fine without it?



When the machine is behaving itself then it seems to work ok, but would it have less random errors with these 2 parts fitted?

This is the fuse fitted in the spindle and servo drive, maybe the power supply should have the same fuse?Attachment 356280

[mbservice]

Can you send a pic of the power supply ?
I would suggest its connected to another problem as the electronics were tempramental