Last night I was working on the PIC-EL board
(http://www.amqrp.org/elmer160/board) and rather suddenly I could no longer
program the PIC.  Now, I had been soldering/desoldering and generally
mangling things, so I suspected perhaps I got something unglued.  In poking
around, I burned myself on the regulator.

OK, this experiment I've run before.  7805's will valiantly try to pump out
5 volts into a direct short, getting astonishingly hot in the process, but
the programming LED would still light, so I had some 5 volts there. More
poking around and I realized the PIC was getting pretty hot, too.  Pulled
out the PIC, board draws reasonable current and nothing gets hot.  Well,
maybe I somehow dislodged the short.

Put the PIC back in, everything still gets hot.  Put the scope on the
crystal lines, and no oscillation.  OK, pull the PIC back out, check the
voltages at each pin, they all make sense.  Put the scope on each pin, too,
in case something else on the board is oscillating, but they all draw
straight lines.

In desparation, I plug in another PIC, everything works just dandy.  Put the
old one back in and nothing but heat.  I've abused a lot of PICs, many much
worse than this one, and was never able to damage one.  Not sure what
happened to this one, but now it's able to draw a bunch of current and get
quite toasty in the process.  Quite a surprise.

One more for the experience log, and very glad that the parts drawer is
relatively deep in PICs.

72/73 de WB8RCR    http://www.qsl.net/wb8rcr
didileydadidah     QRP-L #1446 Code Warriors #35

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