Uh oh... we are moving backwards here it seems. :-(
If you put the EAROM's back the way they were, can you get the one board
to save HS's again?
If so, then, I would suspect that the EAROM that did not save scores in
either is bad and needs replaced.
In the boardset that does not save HS's with either EAROM, there must be
something else between the CPU and the EAROM that is the problem. You
have eliminated the power supply so I would start probing the chip
select line to the EAROM and make sure it is actually pulsing. If it is
not, then there would be an address decoder issue. If it is pulsing,
then you might want to check for stuck pins on the address or data lines
to the EAROM. Im guessing that the EAROM is directly on the data and
address lines so I would not suspect that to be a problem unless you
have a sliced trace somewhere on the PCB. Look for other 'trace'
problems on the PCB too... bent pins shorting into traces underneath,
cut traces, etc. If you have logic probe, you can compare your pin
activity between the two board when one is working and one is not (put
the suspected bad EAROM in the suspected bad PCB and compare against the
working PCB and EAROM)
Bob Langelius wrote:
>Hello All,
>I had one board that saves HS and the other does not. Thinking it was a bad
>earom I swapped earoms. Now none of the boards will save HS. Is there an
>initialization process for the earom?
>
>In addition I have changed the caps in the HS section. And the earom is
>getting -28V.
>
>Any ideas?
>
>Thanks,
>Bob
>
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Received on Tue Oct 4 15:36:53 2005
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