Hi.?
I will try to probe?the logic circuits later today?but?would like to clarify first?if pins 17,18, 23,?24, and 25 of U17?should be high (meaning 3-5v) for the K1000 to boot??
On Saturday, February 13, 2021, 1:32 AM, mjkirk12 via groups.io <mjkirk12@...> wrote:
If RESET_IN is low, then U44 (74AC05) should invert to give RESET* as high signal to CPU
Possible causes:
1) U44 not getting + 5V power
2) U44 is bad
3) Some other device wired to RESET* is shorting to ground (pulling low)
But you also said RESET_IN at connector was not changing - that needs to be repaired as well.
