Smoke on the Horizon... oh s**t!

From: <(>
Date: Tue Feb 17 12:19:48 2004

> Tom> Big, huge, gargantuan, monster arrays of dipped silver mica
> Tom> caps? Seriously, I think you just have to change them often,
> Tom> eg. decadely.
> Actually, at least in switching power supplies, ceramic capacitors are
> now a good option. You can get ceramics of several hundred
> microfarad, and they are quite small. More expensive than tantalum, I
> expect, but more reliable. And if they do fail, they normally fail
> open, not shorted as electrolytics do.

Not only that, will be found shorted, even leaking like a resistor.
Seen these happen with ceramics. When they leak or intermittently
shorting gets you chasing all over. But many times I stop and stare
at schematics and think, try a area where a component is most likely
is failing. Also even a service mode that lets me disable or adjust
a item was helpful. This usually nails it.

Even a semiconductor stuff is known to leak or make signals
intermittent or constantly jumpy (volts) or jitters (waveforms).

Optical coolants (same stuff as anti-freeze) soaked resistors
(especially flameproof & fusible resistors) resistance went down and
blow the semiconductor IC eg: vertical IC after awhile. Made repair
more diffcult till I found out why.


Wizard (working on TV, projector & monitor for shop).

> paul
Received on Tue Feb 17 2004 - 12:19:48 GMT

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