Schematic/Service manual needed for EE Tools TopMax Programmer

I picked up an EE Tools TopMax universal device programmer at the flea
market recently.  It appears to be in fine shape, but it fails the
hardware test in the Windows software.  Some functions seem to work OK
(e.g. the 74xx logic test/identifier), but I haven't been able to
successfully program a 27C256 EPROM, so I suppose it really is faulty.

  I opened it up and there's no obvious damage inside, and the +5/+12
power supply voltages are OK. The PC boards inside have a 1998
copyright date on them, BTW.

  Does anyone have any schematics and/or service information for this
programmer?  These guys cost about $1K new, so I hate to throw it away
with out at least trying to fix it.

Thanks,
Bob Armstrong