I have been using a Unimat PC for about 10 years - nice little machine. A while back, it stopped running - blew the fuse as soon as I turned it on. I localized the fault to the speed/direction control board. I was in the middle of a project at the time and simply tied in a regulated DC bench supply - been using it ever since but I have decided to try and bring it back to it's original configuration.

I can't imagine what/how the control board works. It is incredibly complex for what appears to be a simple voltage control function - 4 CMOS power transistors, a couple of voltage regulators, 8 ICs, 60 resistors and a few other components as well.

A replacement board is apparently available from Austria but the price is astronomical ~ $500.00 so I'm either going to do a board level repair or keep looking for a used one.

Guessing that the power components are the most likely to fail, I've picked up replacements for the power transistors and voltage regulators but, in case that does not do the job, a schematic would be very useful (Emco did not include one in their otherwise detailed instructions and parts list)

Any help or suggestions will be greatly appreciated.

Pretorien