TOM is Ill

[Tom Droege <tdroege@veriomail.com>]

We have had some thunderstorms the last few evenings, and when I turned on 
TOM to test some new software it did not work.  It took me a while to 
notice that the -15 and -5 power supplies were sick.

OK, it is time to initiate over/under testing on the power supply 
voltages.  I do this visually on turn on, but have never gotten around to 
automatic testing.  So a word to software developers:  Be sure to put in 
appropriate tests on the power.  That is why I take all those 
measurements.  I would suggest +/- 0.5 volts for most items.  Nothing is 
critical.  Well, there is the VCO reference and the ADC reference.  I would 
measure where they are and alarm on 0.01 volt.  It is more a question of 
the noise in the measurement system.

Sigh!  I checked the power supply in TOM and it is OK.  So next is a board 
by board test to isolate what has burned up.  It has to be something 
significant to shut down the negative supplies.  Probably some electrolytic 
capacitor has gone to capacitor heaven.

Tom Droege