HP Laserjet Printer Repair
Revision as of 12:25, 27 August 2005 by 192.168.254.89 (talk) (→HP Laserjet 4, 4plus, 4M, 4Mplus and 5/5M printers)
HP Laserjet 4, 4plus, 4M, 4Mplus and 5/5M
Initial Test
- Check to see if toner cartridge and fuser are in printer, add paper
- Plug in and power on the printer and wait for power-on self test to finish, listed for grinding noises
- Run a diagnostic page
- Put into offline mode
- Press menu until "TEST MENU" appears
- Press item until "SELF TEST" appears
- Press enter to print the page
- Check page count and print quality
- If things look and sound okay, continue with Disassembly
- If bad noises or no printing happens, mark the printer for part salvage and repair
Disassembly
- open up the cover, take out the toner cartridge and put it in a dark place
- take out the paper tray
- take off the right side skin (carefully press in two tabs)
- drop open the back cover (if you lose the spring, you can replace it with a Bic pen spring)
- Unscrew the 2 fuser screws and take out the fuser, check it for wrinkles and dirt
- Take off the top of the printer:
- unscrew the two screws on the back of the printer FIRST!
- unscrew the one screw on top
- press in the two tabs and gently lift the top up and tilt it right
- unplug the user interface cable connecting the top to the printer
- Take off the rear exit transport by pressing in the two small white tabs and lifting it out
- take the top panel off the exit transport by pressing the tabs and snapping off the top
- take out the top roller and treat the thicker rollers with rubber rejuvinator
- snap the top back on and save for later reinstallation
- Check the main drive gear in the back for broken teeth (it drives the fuser)
- Open up the memory door for later blowing out
- Take off the small black panel on the front of the printer by pressing its tabs together (they exist on either side of the front panel clasp)
- Open up all internal panels and metal lids to check for paper remnants
- take off the left skin by pressing two tabs and lowering it to the left
- take off the right front panel with the cartridge slot in it
- be careful of the tab on the bottom of the printer as it breaks off very easily
- There are two internal tabs that need to be pressed down through a hole in the right side of the printer as well.
- If broken, take off the single sheet feed tray
- detach the upper half of the tray from the lower by carefully squeezing together the two pivot points
- take off the horizontal metal strip (with spring clip on left) (two screws)
- take off the bottom piece by carefully bending the plastic to sneak out the two pivot points from their sockets
- release the spring (on the left side) from the top plastic piece and remove it
Cleaning
- Clean off both feed rollers with rubber rejuvinator (large rubber wheels to pick paper)
- For the bottom feed roller, press the clip to remove it and rotate the rubber band to bring new rubber into the worn pick area
- Blow out everything with compressed air and clean all surfaces
Reinstallation
- Put rear exit transport back on. Slide pins into slots and click in two tabs
- don't forget to slide on the metal clip on the left side of the printer
- Put front single sheet feed plastic parts back on
- put horizontal metal strip with left side spring clip back on
- clip the two plastic pieces back together
- snap the small black front cover back on
- snap the front right panel (with cartridge slot) back on
- reinstall left panel. Put base tabs in and snap into place
- screw the memory door shut
- Put the top back on:
- connect the user interface panel cable
- snap the top down onto the printer
- add one screw in front-top and two screws in back
- Re-install fuser with two screws
- close the back cover
- re-install right side skin with tabs in bottom and snap into place
- put the toner cartridge back in and close the top toner door
==Testing==\
- Run another diagnostic page (see Initial test above)
- Connect to Linux PC and print a CUPS test page
- leave both pages in the printer, add a price and put it in the store or on the "for-the-store" shelf
Most common problems
- rubber rollers on exit transport are shiny and smooth (z-fold paper jams)
- main drive gear running the fuser is broken or missing teeth
- the front pick roller is dirty or smooth
- the lower feed roller is dirty or smooth (rotate the rubber band)
HP LaserJet 4L, 4P, 5P and 6P
Initial Test
- Check for paper and toner cartridge
- Power on the printer and run a diagnostic page
- 4L - press single button
- 4P - cycle through menu and print self-test page
- 5P/6P - press both buttons at same time
- If no nasty noises and page looks reasonable, continue with cleaning
Disassembly
- Open up top cover, take out toner and put it in the dark
- Take out the 4 screws on the top
- Take off the left panel with the small clip (slide forward and comes off) (not 4L)
- Take out the SIMMs, if any to prevent damage when rolling on its side (not 4L)
- Take out paper tray
- Take off the top cover
- there are lips on the back, loosen up the front first
- you might have to open up panels for the cover to lift off (rear door on 4L)
- Take off the fuser cover, pinch the clip on the right and slide right. (not 4L)
- Take out the 4 fuser screws (only 3 for 4L)
- Take out the fuser, look for wrinkles and dings on the teflon roller and pressure roller
- Inside the front-top, take out the upper paper guide screw and take out the paper guide.
Cleaning
- Blow out the inside of the printer with compressed air and clean out the fan
- Blow out the fuser and the removed upper paper guide (especially the white pulley)
- Clean the black roller with alcohol or rubber rejuvinator
- Clean off the initial rubber feed roller (squeeze clip to come off (not 4L))
Reassembly
- Put the rubber feed roller back on and make sure the clip clicks in (not 4L)
- Put the front paper guide back in and put in screw
- Put fuser back in and add 4 screws (3 for 4L)
- Put the fuser cover back on and click to the left (not 4L)
- Clean exit rollers
- Use two small flathead screwdrivers to pry out and push up on white plastic clips
- Wet rag with rubber rejuvinator and twist rollers in rag to clean off shinyness
- Blow out the top case cover
- Clean the case with Simple Green and rags or Scotch-Brite pad
- Carefully put the top back on
- corners should slide down into slots
- snaps should go down into holes
- Add 4 screws on top
- Put the toner cartridge back in
- Put the SIMMs back in (not 4L)
- Put the left cover back on (slide on carefully and slide backwards to click and lock)(not 4L)
- Clean the feeder roller on the bottom
- Clean out the bottom with rag or blower
- Put the paper tray back in
==Final testing
- Print out another diagnostic page
- Attach to Linux PC and print out CUPS test page
- Bundle with wrapped up power cord and two test pages
- Put in store or on "for-the-store" shelf
HP laserjet 1100
What the lights mean
<insert picture of printer lights here>