Re: Power supplies keep crapping out on me

[grent@comcast.net]

 Hi,
  It might jist be the off/on switch just went bad. Not sure if the
IIes PS had any kind of fuse in them.
  If you need a few P.S. drop me an email. Tying to send a Email from
the via the way the google groups you can not remove any thing from the
email address.

TaKe Care
Scott Alfter wrote:
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> For the past couple of years, I've been running one of my spare Apple IIs
> 24/7 as a temperature controller.  Given that people (including me) used to
> run them as BBSes back in the day, I wouldn't think this would be a problem.
> However, I've now had three power supplies fail on me.  It's used to switch
> the compressor of a refrigerator on/off, which I use to keep fermenting beer
> at the proper temperature.
>
> If I don't have a beer fermenting, I'd ordinarily switch the computer off.
> It should fire right back up when I want it.  After the first two failures,
> I decided to keep it running all the time, setting the temperature above
> room temperature when it wasn't in use (so the compressor would never kick
> in).
>
> The most recent failure was sometime last week.  I briefly considered
> shutting the computer off during a particularly nasty storm that hit Las
> Vegas Monday evening.  A nearby lightning strike must've induced a surge in
> the cable to the temperature sensor, causing it to lock up and return
> invalid data.  (A similar surge must also have been induced into the HVAC
> wiring, where it zapped the settings in the thermostat.  It's worked
> properly since then, once I reprogrammed it.) Turning the computer off for a
> few seconds and turning it back on worked OK, but then I decided to just
> turn it off and leave it off.
>
> When I went to switch it back on a few days later, though, it wouldn't power
> up.
>
> I have it on a UPS, so it should be protected from "power nasties."
> Previous failures haven't occurred near storms, so I don't think last week's
> storm had anything to do with the failure.  (All of the other computers I
> have are still running.)  The power supply that failed this time, IIRC, is
> one in which I drilled a bunch of holes in the side for extra cooling maybe
> 15-16 years ago, and other than a RamWorks II, this particular IIe doesn't
> have anything particularly power-hungry in it.
>
> The last time I popped one of the failed supplies open, I didn't see
> anything obviously wrong.  No capacitors had blown open, and it didn't look
> like any other parts had let their "magic smoke" out.  I suppose that
> 20+-year-old electronics could now be getting to the point where it'll fail
> more often, but is there some fairly common failure mode that I can check to
> see if I can get these power supplies working again?  I could hack in a
> microATX power supply (my "stealth GS" runs one of these now) or pick up one
> of the GSE-Reactive supplies, but if I can get the original power supplies
> working again, I'd think that'd be better from a standpoint of keeping the
> machine closer to stock condition.
>
>   _/_
>  / v \ Scott Alfter (remove the obvious to send mail)
> (IIGS( http://alfter.us/            Top-posting!
>  \_^_/ rm -rf /bin/laden            >What's the most annoying thing on Usenet?
>
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