H7861 PSU issues

Noel Chiappa jnc at mercury.lcs.mit.edu
Thu Nov 2 08:25:38 CDT 2017

    > From: Aaron Jackson

    > Picked up a few 555s and sockets and now it works!


It's odd that a 555 failed, but sometimes there's no rhyme or reason to what
fails. E.g. I was fixing some broken M7859's (KY11-LB Programmer's Console),
and on one of them a 7493 (4-bit counter) had died. That's not one of the
'problem' 74xx chips, like ISTR the 7474 being?


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