24 Apr
2011
24 Apr
'11
3:32 p.m.
Yes, one can get lucky that way - and I have machines in my personal collec=
I must have been exceptionally lucky, then. I think all my HPs, all my
Philips machines and all my PDPs have their original capacotrs. Oh wait a
second, I did haev to repalce _one_ in the PSU of the 11/44.
tion where I have not replaced the filter caps (yet).
Component tolerances=
can allow continued functioning even with significantly degraded component=
s. But if I turn one of those machines on and it doesn't start up, that's =
my problem. If I turn the key on one of our machines at work, in front of =
a crowd of people, and it doesn't start up, that's a different story. =20
Sure. You have to consider what hte 'loss' is if it fails in use. This
may be in terms of lost time/profits, it may be in terms of damage ot
other components, etc.
It's like the comment we had a few weeks ago that desoldering an IC will
reduce its reliability. This is probably true, but as I said at the time
it's not something I've ever noticed, and I've desoldered and refitted
many ICs. In one of my classic machines it doesn't matter id an IC fails
a little beofre it otherwise would have done. Dor something
safety-critical, or whatever, it wouldn/
Industry studies (work by Cornell Dublier) show that aluminum electrolytic =
capacitors have a limited life span. (The most common failure mode is not =
Sure, and I undersntad the reasons for it. But I am not convinced it's
tyhe problem that some people make out.
drying out, it is elevated ESR.) Then there have been
the various scandals=
about substandard components. I think it bears consideration that electro=
Said scandals tend to involve relatively modern components, not the ones
I am talking about.
lytic capacitors are not one of the most reliable
components in our informa=
tion systems. --- Ian=20
I don't know....
Certainly Iv'e replaced many more 2114 RAMs than electrolytic capacitors
over the years.
-tony