« Reply #3 on: January 12, 2018, 06:35:17 pm »
More research in the board descriptions from the Service Manual shows that 671-4164-02 was used in Serial numbers up to B039999.
Then Acquisition Board 671-4770-01 After Serial # B040100.
Another site Keithley/Tektronix forum had a member that had CPU/Dram Board 679-4349-00 in a later series unit same as mine.
Going to be reading up on his attempts which match mine. Locked at Tektronix Splash screen.
Thanks for the ongoing suggestions. I tried changing Pin 3 but to no avail.
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