[ICOM] IC761 problem

[zl3kr]

Having repaired the power supply in my IC761, on the surface it appears 
to be working with the digital readout tuning ok and bandswitching ok
but it sounds like the frequency is uncontrolled as if there was a PLL 
oscillator unlocked with various hetrodynes drifting across the band pass
and it does not receive anything on the frequency it shows it is tuned 
to as I have tuned a Grid Dip Oscillator across that frequncy.
With my limited knowledge  I am not sure if the PLL oscillators in the 
radio also control the digital readout or not.
Any suggestions as to the likely place to look for the problem please??

Alan ZL3KR