17 Jul
2015
17 Jul
'15
12:20 p.m.
-----Original Message-----
From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of tony
duell
Sent: 17 July 2015 19:56
To: General Discussion: On-Topic and Off-Topic Posts
Subject: RE: PDP 11 gear finally moved
given
Perhaps. But not all of it, certainly. I'm currently four for four
fixing dead flatscreens by re-capping their power supplies; I imagine
others have similar experiences. It's not a huge stretch to imagine
This could be taken to show that modern capacitors are not reliable, and that there are plenty of 40-year-old ones still in use
in various classic
computers here it would be better to leave them as-is
More seriously, a lot of modern consumer stuff seems to have
marginally-rated
capacitors (and the use of 85 degree ones doesn't
help). Possibly on those
it is a
good idea to replace them. But the ones in PDP11s were
good quality at the
start and were over-spec'd in general.
be
that other power supplies may have similar
issues; even if it turns
out to not be the case, there is probably at least a little "can't
hurt anything, right?" running around.
Ah but it can hurt. Damage to the PCB (unlikely, sure), the new part might faulty and thus introduce more faults, you might make
an error fitting it,
and so
on. I prefer to only replace that which needs
replacing.
-tony
=
When I repaired my VT100s I had to replace all the electrolytic caps on the
monitor control board to cure the screen wobble. Before doing so I had
reformed them all and I had tested them all for ESR and they had all tested
fine so I was unable to determine which of them was the bad one. Perhaps
there is other more professional test equipment I could use that would have
helped, I don't know. I did keep all the original caps though (somewhere).
Regards
Rob