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Cydrome Leader

wrote:
wrote:
FADAL 1040-2A INTERFACE CIRCUIT BOARD DEVICES

All that TTL. We're gonna party like it's 1979!

After seeing this parts list, I'm gonna re-suggest checking the power
supply to this board, probably +5 V DC. If it's at all low or high, you
might look into why that is. (TTL parts draw relatively a lot of
current from the +5 V supply. Some of yours draw less - the 74LSxx and
74ALSxx part numbers - but in general, TTL boards require stout power
supplies.)

I'm going to agree on both points that the board is a "classic" and that
it may be time to check the power supply. It may even be that the cool off
period the board gets when you mess with connectors is really doing the
magic.

If it's safe, I'd run my fingers across the chips to see if any are hot
just after the machine acts weird. The 7400 stuff will warm up, but should
not be hot.