Re: Working on a //+

[pausch@saaf.se (Paul Schlyter)]

On Sat, 22 Sep 2001 07:51:02 -0400, Tom Zuchowski wrote:
 
> Ralph, don't waste your time testing the capacitors. If they are ten
> years old, they should be replaced. Heck, for these older caps that
> we are discussing, they should generally be replaced when they are
> six years old
 
You seem overly pessimistic about the lifetime of capacitors....
 
I'm posting this on a 13-year old PC.  No capacitors were ever changed
there, and it still works fine.
 
My own Apple II+ is 21 years old -- its power supply still runs fine
even though no capacitor was ever changed.  It does have problems
with oxide at its slots and cards though.
 
Last summer I bought an old radio at a flea shop.  It was
manufactured around 1956 -- yes that's 45 years ago!!  I had to fix
some mechanical stuff to get it working OK, but the electronics
worked fine -- no capacitor needed to be replaced - it would actually
be quite hard to find the high-voltage (300 to 400 Volts) capacitors
needed there: it runs on vacuum tubes, not transistors.  For its time
it was quite modern - besides the common long, medium and short wave
bands it also had the FM band (although the "old" FM band which ran
from 88 to 100 MHz; nowadays the FM band goes all the way to 108 MHz).
The reason I bought it was pure nostalgia: when I was a little kid
my parents bought a radio of precisely that model.  I was surprised it
worked so well - I had expected at least some problems with its
electronics, but it works just fine.
 
Thus capacitors need not necessarily be changed after 6, or 10, years;
some work fine even after 45 years!
 
-- 
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Paul Schlyter,  Swedish Amateur Astronomer's Society (SAAF)
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