[comp.sys.3b1] POWER SUPPLY DIED

s9115@gte.com (Sohail Zafar) (06/10/91)

Hi everyone,
    This is my third attempt to post. I think the last two never went
through. So the story is that....
    My power supply just died from a power surge.  I traced it down to two
components. One is transistor Q 1 which is marked as STI-8503 and 8442 below it.
It is completely shorted so I don't know whether it is a PNP or NPN. I tried
two electronics stores but there is no cross reference to any equivalents.
The other component which blew looks like a thermistor or something. It is 
marked as RT 1 and the number on it is SC-220 located near the two rectifying
diodes CR 1 and 2. If somebody who has the Hardware reference manual, could
please look up and tell me whether Q1 is pnp or npn or if anyone knows about
any equivilants I would appreciate the help very much. I am presently using a
IBM AT power supply but that is giving me hard disk errors due to poor rating
for +12V.

Thanks to anyone who responds.

zafar@phoenix.src.umd.edu