In article , Bill Turner
writes:

On Wed, 14 Apr 2004 23:09:40 GMT, Allan Butler
wrote:

there have been rare cases where a new capacitor surprises the new owner
with a loud bang.

_________________________________________________ ________

This is so rare as to be a non-issue. If a new electrolytic goes
"bang", you have almost certainly done one of two things wrong:

1. Installed a new capacitor with too low a voltage rating.

-or-

2. Installed the new one backwards.

Or both. :-)

Otherwise, don't worry about it.

Bill, I have to agree with you. This is a NON-ISSUE.

Having had some experience in electron-pushing, mostly hands-on,
since 1947 (which includes those "B+" high-working-voltage
electrolytics lots are so "afraid of" nowadays), I've been through
the same two boo-boos you mentioned...but only a few times and
that was long ago.

I've got a few electrolytics that have been around since the year
dot in the workshop and they still measure good enough, with
or without this "re-forming." Those were obtained some time
between 1958 and 1964, putting them 46 to 40 years ago since
first manufactured. :-)

No explosions, no going "poooof," just sitting there doing their
thing, tack-soldered into a quasi-breadboard for a hybrid "B+"
supply that is regulated and I'm interested in trading off how
much capacity needed for achieving a reasonable regulator.
Not building a production prototype, not worried about a job if
10,000 ordered parts will be scrapped if the wrong thing is
ordered or worried about future QC shouting and hollering about
"failure rates." It works or it don't.

This is a HOMEBREWER newsgroup. We aren't building space-
craft that must operate unattended on Mars. We should have
- as hobbyists on the bench - some kind of power supply handy.
It's a bloody simple task to just get some clip leads and a handy
series resistor and roll up some voltage from whatever supply is
there, then see if the electrolytics can hack it. Takes at most
a half hour to set up, do it, make notes, take down...about the
time needed for some to sit and agonize over problems they
don't have yet on the Internet. Geez, at worst, a cap will get
fried and a new one has to be bought. Maybe. One #$%^!!!
better than "replacing _all_ 'old' ones" as another suggested.

Len Anderson
retired (from regular hours) electronic engineer person