yes, so much synchronity would be very unlikely.
Sometimes unplugging/replugging cards and bus cables helps with vintage audio gear.
(I have a Creamware DSP system of similiar age that occasionally has contact 'symptoms')
Be careful not to touch contacts with fingers.
Pure ethanol (from the chemistry) is a good cleaner, but beware of the stuff used to light up grills, it contains some oily components.
Of course a (partly) failing PSU can have influence on output drivers and it may introduce electric noise into the circuit.
My 882 has a kind of suspective power-up noise (low level deaying beep of a second or so when regulation swings in), but no flaws in performance yet.