On 08 Aug 2005 11:07:27 -0400, Sam Goldwasser wrote:

"DS" writes:

I have a 12 volt power supply that converts 110AC to 12V DC (actually 13.5.)
I haven't used it for some time.
I was using it to check some wiring and find it is now putting out 21 VDC.
???

As someone else noted, check it under load. But if it is the typical
Radio Shack or similar "12 V" power supply, then it probably is a regulator
problem, possibly just bad solder connections or a shorted transistor (though
that wouldn't happen from sitting around).

but using it for "testing wiring" may have applied a short and let the smoke out
of the series reg device ...