"Mike Coatham"

My Fm4 has a strange problem, I have replaced the back up battery and
this
is working, if I store a station at 88.10 mhz when I switch it back on
the
frequency comes up at 88.00 mhz for the first 5 - 10 minutes, it then
slowly creeps up to 88.5 then 88.10, it does this on all stations stored.


Remove the MP4480 custom chip from its socket and re-insert it. This
sometimes cures spurious or erratic performance.
Considering the age of the Tuner, the socket contacts are likely not as
good
as they should be and the process of removing & re-inserting the chip will
clean up the contacts. Personally I would replace the socket with a new
one.
If this doesn't fix it, you are likely up for a new IC - which are
available
from Quad at about UKP26.00



** After carefully examining the schematic of the FM4 - I reckon Mike is
pretty much right on the money here.

Your Quad tuner's problem is most likely some kind of corroded contact,
stray leakage or PCB dirt and dust contamination issue.

Just needs some TLC.






....... Phil