[comp.sys.zenith] Power Supply Problems

ram@kepler.unh.edu (Richard A Messner) (06/18/91)

First of all I'd like to thank everyone for the many helpful replies I
got in regards to the hard disk info I was asking for.  If anyone would like a
summary, please leave mail (I got some conflicting data, but I should have
it sorted out soon).

On to other business - recently the power supply in one of our Z-248's burned
out.  Can anyone point me to some schematics or other technical info?  All the
components inside seem to have Zenith in-house part numbers, so even if the
faulty component is found, there's no easy way to figure out what to replace it
with (the problem seems to be the -12 volt supply, which is currently reading
-16 volts).  If anyone has a cross-reference list relating Zenith part
numbers to commercial parts, or something like that, I'd appreciate it.  Zenith
is willing to repair it at a price for which we could probably purchase four
generic power supplies (which may not fit in the case).  The model number for
the supply is ZDS-234-859, and the model number for the computer itself is
ZBF-2339-BK.

Incidentally, a word of warning - these power supplies seem to have poor
protection on the output side.  I know of several cases where a shorted
component on one of the bus cards fried the supply.  If you suspect that
any of your circuits are getting flaky, check it out immediately, especially
if you use these systems for hardware development, as is done here in the
EE department.  Thanks.