how to test psu and reset to cmos to default

hi,
x-posted
this is not a very popular topic as i keep losing people :-)
but i'd appreciate any help.
ibm aptiva 2159-s90 (1997; split system; win95B) SUDDENLY for no reason,
had post-start-up errors (date and time change (they hadn't changed) and
config change -- referred to the floppy drive))
the floppy was fine (basically) i changed the battery last pm and it
wouldn't pass the post (at all)
cleared the cmos (paper btwn clip and battery overnight)
it booted this am; many post-start-up errors (some phantom)
currently: the cd-rom (in the media console) is running however the pc
won't recognize the win95 cd (the cd-rom is set as the 4th start-up
device)
the post-start-up error now is: "adapter card resource error" which i
think refers to the media console controller card (since it's in an isa
slot)
i have NO CLUE what to do about that.
so i want to get the pc to reset to factory settings and don't know how
to get this (it is not listed (although it used to be))

i need to test the psu and want to make sure that this is correct:
i'd put the positive (red) probe (backprobe) to for example the red wire
on the power cable to the hd and THEN ground it (for example using the
p8-6 and p9-1(the center black wires on the power to the board
adapter?))
any help is greatly hoped for and appreciated