[TenTec] OMNI VI Model 563 -- no digital readout (Peter Bertini)

[Peter Bertini]

Greg

U13 will not cause the problems you are seeing. It phase  locks the HFO
crystals to the master oscillator.  If it is not locking, all that will
happen is that rig will be off frequency on that band, and signals will
sound warbly as it sweeps the varicap for those crystals trying to achieve
a lock.  Operation is verified by a very narrow and stable negative going
pulse on pin 11 of U13.  I usually crank the 100 MHz scope to max and
trigger on negative to see the pulse.  Each crystal is warped by an
adjustable coil, and is tuned for minimum pulse width.

I am not an expert on the Omni VI, just have some experience fixing up
several parts rigs for the fun of getting them going.

The board appears complicated because of the clutter added by the DSP
circuitry and the clock chip. I'd ignore those sections and instead I'd
suggest concentrating on the CPU that controls the display, band functions,
etc.  Look and make sure the data lines are showing activity on the CPU and
ROM data lines.
Reset lines not active, etc., CLK signal is on the CPU...

Vcc is at around 5.5 VDC at the regulator?

You said you changed some electrolytic caps... make sure the polarities are
correct.

Pete