Hurco KM3 servo problems

I've been searching the net for quite a bit recently looking information on my Hurco and the problem, and this seem to be the place with the knowledge to help diagnose and hopefully fix it.

It is a KM3, with manual speed adjuster, no tool changer, and the original BX controller. The masters are still loaded by tape (If anyone can supply an emulator or suggest how to get the masters onto a 720kB floppy, since I do have the Hurco tape -> floppy emulator, I'd be very happy too)

The initial problem came from a poor connection between the Y-Axis and the cabinet, leading to a short and some burning of the cable. A replacement cable was made up as to the specifications of the manual, and was in agreement with the removed cable. Once this was installed, however, I found the encoder for the Y-Axis was dead, and so a replacement was ordered and installed.

Once the new encoder was installed, when the machine was in operate mode (With E-Stop down) I could see the encoder count when turned by hand, however, when I powered up the servo system, I found the Y-Axis driver board displaying the SC light. This was fixed with the replacement of the power transistors on the board, and the system was then energising all 3 axis drive boards.

When the machine was given some commands, it initially seemed promising, as it was performing the requested operations (Some dry run circles only, with the spindle engaged), but after a period of time the machine started to lose count on all the axis, then moved erratically, finally just moving in the direction the servos were originally moving in when the counting stopped until they all hit the stops, or E-Stop was applied; it would not 'count' again until powered off, and the master reloaded. This working period got shorter and shorter, until this morning, when it would not count at all and now seems to not see any encoder, on any Axis.

I have read this thread (KMB-1m Runaway) in which Buddy seem to diagnose this as being a Servo Control board problem, and the symptoms described are almost identical to mine, there is no resolution, however.

I wonder if anyone can offer any advice, or possible solutions to this problem, as I'm stuck without this machine? If it is only a matter of replacing a damaged or failing component on the board, I would be able to do so. Hurco Europe and the local Service guy have said they would not be able to offer help with this problem. Since I'm based in Northern Ireland, getting repair work or new parts from the U.S. becomes very pricey!

If I can't get this sorted, I'm afraid I'll have to rip the machine apart and do a conversion, something I'd like to avoid if possible!

EDIT: See attached pictures for serial numbers and additional daughter boards, if this will help with identification.

http://www.cnczone.com/forums/attach...d=332486&stc=1http://www.cnczone.com/forums/attach...d=332488&stc=1

Have you checked your 5V voltage? It sounds like you may have an encoder voltage problem perhaps? If you shorted higher voltage to the encoder y encoder you may have damaged the 5v bus. Did you try a "new" servo board? Which amps do you have?

Thanks for the reply B.Reilly, I don't have a spare servo control board to try in the machine.

I have the Servomate / Randtronics servo amp system, with EC servos. Where would be the place to check the 5v voltage? Following Buddys instructions from the referenced post, I am seeing the encoders on pins 1 & 2 for all three axis, so I know the encoder pulses are getting to the board.

I was also getting some slightly off readings from my power supply, so it's been replaced and all outputs are stable and at the right voltages.

I can't see an exact match of my servo control board in the usual places, but I can see one with an E suffix ( 415-0142-001E, Mine reads 415-0142-001M), does anyone know if this will be compatible with my system?

Finally managed to get a compatible Servo Control Board (415-0142-001K revision) and now my machine is back up and running. I need to try and find some new masters, though, and I'll post about that separately.

Steve,
I haven't been on here in a while.
I did a retrofit and have some spare drives and boards, etc. That came out of my machine.
Would you be interested in these for spares?
Let me know.
Thanks
Jack

Sent from my SAMSUNG-SGH-I547 using Tapatalk