Fuse 12 Blowing on 1985 Boss 8 CNCMill (V2E3)

[kebell03]

I need to figure out what fuse 12 is going to. Fuse 12 blows right as I turn power on to machine making unable to start up drives and to perform any basic functions with machine. Nothing displays on the main screen for the machine.

[isu19151@verizo]

I have a 1986 R2E4 boss 9,had same problem,installed bridge rectifier (BR1).It stopped fuze 12 from blowing but I still have drive issues.I figured this out by using wiring schematic and bridgeport troubleshooting procedure in manuals.

[MrBoss8]

Fuse #12 is a mdl 2 amp 125v. This is the +24v power supply used for the Estop, limit switch string, some operator switches, and the EAF board in the rear power enclosure. Check these areas for shorts "after" checking the 24v supply for output problems.