---working from memory as the printer is in the office ---
BEFORE you try removing the top case you need to remove the power supply
cover- this is the rectangular plastic bulge housing the power connector
and parallel port. You need a (pair of) thin bladed screwdrivers or kitchen
knives to release clips on the left and right sides of this casing, gently
pull out horizontally.
For the top case- look under the printer and you will find 4 slots, two at
rear left and right, two at front laft and right, which if you gently probe
with a narrow flat head screwdriver will release clips which hold the
plastic top case securely to the metal base. With a bit of dexterity
required you will get all 4 clips disengaged and simply lift the cover. Some
wiring connects the front panel to a rear board - the wires can be unplugged
from the main board easily to allow full removal of the plastic case.
Once open if you need to go deeper you may need a smaller torx head for some
of the components. Most of the drive bars are held by plastic bushings which
can be released easily by partial rotation.
From memory in addition to a pad to soak surplus ink in the base there was
also a "tank" to the left of the cartridge parking area in which a large
waxy stalagmite of ink was growing - I used a tweezers to pull out most of
this. You also need to rotate a drum in the parking area and clean the
various wipers and rubber seals on the drum.
I opened same model recently as it was suffering from paper path problems -
if your suffers from poor pickup, multi-page pickup (major jam!), blank
pages within multiple page docs or similar I would advise while you have
cover off etc take out and clean well the rollers (single pickup and
multiple travel)- I used cloth damp with water and detergent solution after
VERY light sanding to clean and remove any glaze. I also pulled the rubber
pickup roller to one side off its mount - do this gently - and packed a
couple of rounds of pvc tape onto the metal bar to thicken it slightly. Cut
locally to let the cam reappear and slide the rubber roller back in its
correct alignment. I dont know if all this would meet the approval of HP but
it has rendered useable a printer which I felt was probably not worth
getting repaired professionally.
