Re: Reforming electrolytic capacitors (was Re: Sony CPD-1302 monitor -- IIGS cable?)

[Eric Smith <eric@brouhaha.com>]

"Michael J. Mahon" <mjmahon@aol.com> writes:
> The problems of "starting up" long-idle electronics is an interesting
> problem, but not the one that I was addressing.  In fact, I have simply
> turned on a lot of monitors that had not been operated for at least ten
> years, and have never (yet!) experienced a failure when doing so.

The five year timeframe I mentioned was the *minimum* that I've seen
this happen, for a capacitor that isn't physically damaged.  Most of
them take longer to deform.  But there are no guarantees.

> The problem I *was* referring to is the loss of capacitance brought on
> by prolonged operation at a relatively high temperature.  This causes
> electrolytics--which are all non-hermetic to allow for venting

Actually they are usualy hermetic.  The top of the can generally has
two score lines so that in an overpressure condition the can will
somewhat gracefully open at the scoring before the overpressure
gets too serious, rather than exploding violently.

Once the seal is broken, the electrolyte starts to dry out, reducing
the capacitance quickly.

Any electrolytic that has leaked, opened at the scoring, or burst needs
to be replaced.