Need Help!- Bridgeport VMC2216 Strange Problem

[Jadaan27]

Hi all. I have a Bridgeport VMC2216 with Fanuc 21i and Yaskawa Servo Drives. I had this alarm come up several months ago "430 x-axis servo motor overheat." I sent my servopack out to get evaluated. I was told it was non-functional and they repaired it for me. I put it back in my machine, and I still had this alarm.
I finally found a 5-amp fuse on the FSSB Module that was blown. I replaced this fuse and when I turned the machine on I had FSSB Alarm 926 come up for a second and then the screen turned to gibberish codes. I shut machine down then turned it back on and all was fine. No more alarms.
I ran machine for about 80 hours no problems. Then recently I had Alarm 430 "x-axis servo motor overheat" occur again. So I went straight for the fuse on the FSSB Module and found it was blown again. I replaced it, and it blew again. I had my servopack evaluated again. All is fine with that. But the fuse on the FSSB keeps blowing as soon as I turn the control on.
I checked the voltage to the FSSB. It checks at 22.25VDC.
I'm thinking maybe bad fiber optic cable? Or bad FSSB?
Anyone ever see this problem before or have any suggestions?

Thanks for any info.

[machintek]

I have not worked on one of these in years but had a set of wiring diagrams scanned into my laptop. I see where all 3 drives plus the 4th if so equipped interfaces with the FSSB. I see V ref going to each drive but the 24 V does not come through the FSSB but is shown below it. It may be that the FSSB supplies 5VDC for the encoders and such. Is it possible you have a encoder cable shorting out? Check them for kinks, cracks in the outside, chips, etc.
I have one of these machines not too far from my house and will try and get a look at it.

George

[Jadaan27]

Thanks for your reply, George.
I checked out my cables and they look fine. I checked them the best I could with a continuity tester. But that's not too say that I don't have a bad connection somewhere in the cable. So I haven't ruled that out yet as being a contributor to my problem.
What I ended up doing was pulling all connections off my FSSB Module except for the incoming 24vDC power. As soon as I turned the control on, the fuse blew. So I sent my FSSB Module out to get evaluated. I will let you know what I find out.
Most all the Hardinge/Bridgeport technicians I've talked to on the phone about this problem don't have any experience with my machine configuration: Fanuc/Yaskawa Hybrid.
It's nice to know someone out there has worked on these before.

Thanks again George,
Jason

[Jadaan27]

I put my repaired FSSB Module back in my machine and all is running fine for now. I hope it stays running this time!
I hope someone else out there can benefit from this info.