Problem- KMB1 Servo Amp

[battmann]

Does anyone have a schematic for a 402-5001-022 Servo Amp for a Hurco KMB1?

I fired KMB1 up the other day, and as soon as I powered up the servo's the z axis retracted HARD and will not move in the (-) direction. I swapped cards with Y, and the problem moved to Y.

I'm fairly comfortable with trouble shooting pcb's to component level, but I need a schematic. I sure hate to pay $700 - $1K for a repair or replacement board... when I know it's probably a $5 component on this board causing the problem.

Anyone out there have a schematic (or, better yet) anyone have experience with this type of problem and can possibly tell me what the problem is.

I would appreciate any pointers, advise...Suggestions.

[DTX]

Manual with everthing you need here:
http://www.skullworks.net/include/Se...e-AO-73187.pdf (14.94MB)

If you can't get that to download, then you can get the same thing from the O.E.M website. You will have to jump through a few hoops first.

http://www.burny.com/Burny_servomate.asp

[gthlm]

Originally Posted by DTX Manual with everthing you need here: http://www.skullworks.net/include/Se...e-AO-73187.pdf (14.94MB) If you can't get that to download, then you can get the same thing from the O.E.M website. You will have to jump through a few hoops first. http://www.burny.com/Burny_servomate.asp

I didn't recognise that part number (the randtronics boards in my hurco MD3 are numbered 800D05...), but if it is the randtronics drive then it's almost certain that it's one of the power transistors on that board shorted out (one of the four that are mounted on the heatsink) putting full power the servo in one direction.

Replace all four of them with Motorola/ON Semi MJ10021 and all will be well. While you're at it replace the electrolytic capacitor next to the rectifier, and make sure that there are no burnt resistors in the power section. When you replace the transistors make sure and put the insulating pads back in (clean them thoroughly or replace them) and check with your meter that there is no continuity between the heatsink and the case of the transistors or you will get a ground fault when you power it up.

One word of advice though, buy the transistors from a reputable component supplier, not from ebay and absolutely not from anywhere in china!

You will most likely need to tune the drive after you've done this, I have the hurco process sheet for this if you need it.

Hope this helps.

[battmann]

Sure appreciate the link to the info, I'm fairly confident I'll get to the bottom if it now. I'll post the results of my success (or) failure, in a couple of days.

[battmann]

Thanks for the info, I'll definately give that a try. More later...

[Hele63]

Battmann,
Try to contact Galco Industrial Electronics http://www.galco.com they are very experienced with repairing electronic boards and are very good with pricing. I would at least call them and they will give you a price over the phone and the part is guaranteed for 1 year no matter what.