HP82240B corded printer conversion reworks

4/2/2011 PJS www.wire2wire.org
(note click on any image for larger version)


1.) Flip printer over onto it's back
Back of printer

2.) Carefully peel off the 4 rubber feet and remove the battery compartmetn door (any any batteries if installed)
3.) Remove the 6 screws (2 in battery compartment 4 under the rubber feet)
Screws removed

4.) Carefully flip over the printer and lift off the top
Top off

5.) Lift off the 3 gray plastic buttons (note orintation will be reinstalled later)
6.) Unplug the 2 cables running to the printer mech. Carefully pull strait up and slightly rock end to end on the base of the ribbon cable to remove it.
7.) remove the 2 screws in the upper corrners of the printer mech assembly. Then lift up and out and place someplace safe.
printer out

8.) Unplug connector to battery compartment.
9.) lift out printer circuit board.
circuit board removed

10.) Remove the following componets (minimum list)  AC wires, CR1, CR6, U1, U3.
AC wires to remove the old AC in power jack to make room for the new data cable.
CR1 to take the diode voltage drop out since the input voltage will be 5V instead of the 6V a normal battery pack would supply.
CR6 to allow power back into the "AC supplied" side so the printer will not go to sleep after a short period of inactivity like it would on battery power.
U1 so the above rework is not back driving that regulator.
U3 to access the decoded IR output signal.
remove U3
remove U1, CR1, CR6

11.) Install a jumper wire across CR1's location
12.) Install a jumper wire across CR6's location
cr1, cr6 jumpers installed

13.) Install a wire into the pin hole of U3 closest to C34 as shown. (This is the data input wire from the adapter). Note I have removed all unused components. This is not nesicary just the parts listed above need to be removed.
signal wire

14.) Remove all the battery contacts from the battery compartmetn. If you look carefully there are tabs you bend up then the contacts will just press out.
battery contacts in
battery contacts out

15.) trim the plastic ridge in the battery compartment as shown to fit the adapter PCB. (I used a fiberglass dremal cutoff wheel)
ridge cut
card in

16.) Cut 2 holes / slots as shown in the back of the battery compartment for wires.
wire holes

17.) String the battery power cable and your new data cable (I used a old 9 pin serial extension cable) as shown. The data cable is routed out the old AC power jack hole.
cables installed

18.) Reinstall the printers PCB and route the data in wire to the battery compartment. Also plug the battery power cable back into the PCB.
pcb back in

19.) Reinstall the 3 gray button caps
buttons on

20.) Reinstall the print head. First install the 2 screws in the upper corners. Next plug in the power cable next to the battery power cable. Lastly install the print head flex cable. Carefully line it up on the socket then firmly press the cable edge down and in till it stops.
print head

21.) Carefully flip the printer over and reinstall the 6 screws. (2 in battery compartment and 4 under the rubber feet)
Screws in

22.) Reinstall the 4 rubber feet. If you were careful when you peeled them off they should stick right back on.
feet on

23.) Wire up the adapter PCB per schermatics. You will need to install the jumper between pins 1 and 2 of the configuration / programing header. The "data in" wire you added to the printers PCB goes to the collector of Q1 where you removed the IR led. The black wire from the battery pack cabke goes to ground. The red wire from the battery pack cable goes to +5V. The data cable can be wired to suit your needs see the schermatics and make sure you supply 5V and ground on the cable to the printer. (Minimum cable config would be +5V, serial in, ground. Max would be all 5 pins)
circuit board in

24.) Install the battery cover. It should easly pop in place. If you need to force it on make sure that the adapter PCB is laying flat in the spot you remove the rib earlier.
battery door on

25.) Flip the printer over and test.
finished