Date   : Wed, 07 Mar 1984 23:32:00 cst
From   : Eaton.HFED@hi-multics
Subject: troubleshooting

Reading through Seymour Joseph's experience with his new Octagon Hard Disk
and controller prompted me to offer this tidbit of info to techies and non-
techies alike.

I personally have an unreasonable fear of sending my S100 boards back for
repair.  This especially holds true for temperature sensitive problems.
If you are experiencing intermittent problems there are a few things you
can try before packin' it up an' sendin' it off to who knows where for
who knows
how long.  If you suspect heat is the problem take a hair dryer and fit the
hose (please don't use a floor model) with a small diameter plastic tube
using tape or whatever.  Let your board cool down.  Then systematically direct
the heat from the hair dryer to each individual chip on the board.  You can
actually heat them to the point that they are too hot to touch and they should
still purr without incident.  If there is a bad chip on the board that's
thermal sensitive you'll find it.

Incidently, heat is not the only way that chips (or transistors) will fail.
Cold can also be the cause of failure.  At present I am using a pressurized
can of freon (tape cleaner) to cool circuits.  It runs down the board and
gives you the impression that it will fry every living circuit on your board,
but it is non conductive and does no harm.  A better alternative would be to
purchase a product called "circuit cooler" which will actually put frost on
your precious electronic gizmos but again, no harm should be done.
Please "DON'T USE COLD WATER OR ANY THING THAT MIGHT BE CONDUCTIVE."  If in
doubt don't use it.

One last thing that you might try is tapping on each chip or banging on
the edge of the board to check for poor mechanical connections, solder
balls and bad
chip seating in sockets.  Don't use instruments made of metal for the "tap
test" as a poorly placed strike could put you out of business for certain.

If you wish, you may purchase commercial products at your local electronics
supply house to make it all a bit more professional.  I have a heater specifi-
cally design to heat electronic components.  And if your board(s) are burried
deep inside a mainframe then it might also pay to purchase a board extender.
Be careful with these because you now have no protection from inserting the
board backwards in the extender.

You don't need technical know-how to perform any of the above.  If you localize
the problem then a component is what it costs (probably cheaper than shipping
your board off "UPS Blue") and your board never leaves your side.

I get queasy (or is it withdrawal) when I'm without mine.

Happy troubleshooting.

Jesse Eaton (Mpls - where March comes in like a lion and goes out like a lion)