Re: IIc problems

["Paul Grammens" <grammens@svn.net>]

"Greg Andrzejewski" <pressyourluck85@yahoo.com> wrote
> something wrong with this machine. I opened the case up and all looks
well,
> except for one capacitor. It's the capacitor in marked C44, just right of
> the volume control knob. The system will not boot (just goes into monitor
> dump mode). The capacitor appears to have been leeking some dark yellow
> ooze. I assume it has exploded. Sometimes the machine beeps upon power up,
> but rarely. Now what? Any thoughts?
>

My educated guess would be that the leakage is shorting some traces on the
PC board, so carefully cleaning that off may get it working again. Take a
close look, that stuff is corrosive and can eat up the copper traces. You
can repair minor damage by tinning the traces with solder. If there is
corrosion, you may need to scrape or brush that off before solder will flow.
Add wire if the damage is severe. The cap is most likely part of the audio
circuit, judging by its location. You can probably just remove it if you
don't care about sound. If you replace it, note the polarity and read the
size and voltage rating- something like 10 ufd 25V. Replace it with the
same, or one with one or both numbers higher, such as 15 ufd 35V.
Good luck!
-Paul