Hi Rich,
I seem to have deleted the old emails. Just to confirm, you have a later
(rev 3 schems) Xa
And we were talking about U164, right
Now you
are saying that only the gnd and +5MEM pins are connected. Is that correct
The 47 pf cap suggestion was testing delay sensitivity for one of the digital
connections to that chip, not the power supply. If only connecting the supply
pins makes a difference, then it's a different sort of problem. On the supply pin,
you can use 0.1 uF instead of 47 pf. Also, +VMEM should already have two caps
to gnd, C4 and C5. Maybe C4 is bad
Sounds like you need to scope +VMEM.
Bob