18 May
2009
18 May
'09
8:05 a.m.
I've grabbed new replacements for all the
capacitors, apart from the
big high-voltage input-side ones. One of the output capacitors has
shrunk its heat-shrink wrapping quite considerably, so I'm guessing
that one has been running quite hot. Might as well replace them all
though - the replacements only cost me NZ$10 (something like 3 pounds,
maybe US$5, at a guess) so it's hardly breaking the bank.
Be careful with the high voltage ones in the input filter before the
diode rectifier. (A couple of uF, 400 or so volts AC rated - encased in
a clear plastic case) I had an apple 2 recently that had one of these
fail spectacularly - tons of brown goo that smelt of cigarette smoke
(tar?) spewed forth. It was hard to remove. But It is happier now.
Also - regarding the drop the 12V rail - isn't that the one that is
monitored to regulate the switcher?
Does anybody have the schematic for these PSUs?
Doug