[comp.sys.amiga.tech] 8520 repairs, part numbers, advice

phil@eos.UUCP (Phil Stone) (03/19/90)

I have had continuing problems with the FIRE pin
on the second joystick port (it seems to have blown
out from a powered-on connection, or static or
something).  I have tried swapping in new 8520's,
but the problem remains the same.  The Amiga always
thinks that the FIR1 pin (9) on the 8520 (U300)
is active.

Through the schematic, I traced the problem to 
capacitor C250.  Sure enough, an ohmmeter showed
there to be a short across this capacitor, which
caused the corresponding asserted (low) condition.

Main Question:

Does anybody know the part number for this cap (C250)?
The schematic lists it as 100 pF, but I don't
recognize the style (see-through, with copper-colored
bands at the ends).  Who sells this part?

Any caveats for replacing the cap?  I'm going to remove
the associated 8520 while I do the cutting and soldering.
I think the new cap can be soldered in from the top of
the motherboard.

Thanks for any info or tips you can give me.

		Phil Stone	 (phil@eos.arc.nasa.gov | ames!eos!phil)