Try re-seating all the socketed chips by pushing them
down firmly into the socket (but not so hard that you
break something).
Also inspect closely all the socketed chips for corrosion.
If there's any corrosion on any of the pins, pull the chip
and wash it and the socket with alcohol. If needed you can
use a soft brisseled tooth brush to scrub with, just be
careful not to bend the pins.
That could solve the HDD problem also.
I use Commodore's FFS, never used SFS.
I've never really had a problem with FFS, but then my main
HDD is a 3.2 gig Quantum.
Mel