Need Help!- 4020 tool changer and fuse #14 blowing

[5th-axis]

We have a 4020 yr. model 2000 with CNC88HS control. On start up the tool changer just continually rotates as soon as it is powered up. I can hit one of the turret jog keys to get it to stop. Any attempt to cold start or jog the axis results in a blown #14 fuse with a resulting fault on x or y axis, depending on which is selected. I have checked all connections and re seated the 1010 cards. Could this be a bad prox switch on turret home?
Any and all help is certainly appreciated.

[Neal]

Fuse #14 controls K1 and K2 relays. Also K20 is involved. I wold suspect that it blows only when the ATC is in operation that the issue may be with the wiring being shorted going to the ATC, the ATC motor shorted, or a bad sensor. The bad sensor usually give a different response than blowing a few. Normally you would get an error code.

Neal

[5th-axis]

Thanks for the reply Neal,
On power up the tool carousel starts rotating. I can hit one of the turret keys to get it to stop. When I hit cycle start to cold start the machine, it blows fuse 14. If I hit manual to jog the machine, it instantly blows. I have cleaned the board under the spindle drive as well as it had a fair amount of gunk on it. I am completely at a loss on this one.
Thanks again for the help. It is appreciated.

[Neal]

From what you describe It sounds like you have a dead short somewhere. Get a bunch of fuses and take all the boards out of the cage except the CPU, Video, and 1030 interface. See if the fuse blows. Try replaceing the boards one at a time to narrow down which circuit you need to witch hunt.
The issue could also be in the amplifier chassis circuitry.
Perhaps it would help to first give the whole machine a very close visual inspection of ALL wiring and investigate any thing suspect.

Neal

Neal

[alex gitzel]

you will also want to swap the relays for the turret,those will cause the motor to spin all the time if one is stuck.

[5th-axis]

We found a burnt trace on the 1100-2h card where coolant had leaked down to it. We replaced that card and the machine will not cold start but it is no longer blowing fuse 14.

[overflowmachine]

I recently had the same problem and it was a relay I'm not sure about the number and will check tomorrow but fuse #14 relay K1 and K2 sound right. It had burned a hole right through the side. I had a spare and was up and running in a snap. My machine is a 4020 from 98. Good luck Ron

[Delw]

I had the same problem with fuses blowing also and it was the relay.
The relay that gave me the problems was in the CPU cabinet on the top right hand board, slot was 1/4 of the way down.
BTW they relay worked sometimes and gave some very weird voltage's