HP Printer Tips:
Fixing unreliable paper feeding and jamming, checking true ink levels, lubrication to eliminate rubbing noises and sticking print heads.

• FIRST THINGS FIRST--SAFETY PRECAUTIONS:
  
  • Turn the printer off at its control panel.
    
  • Unplug the cable to the PC.
    
  • Unplug the power cable.
    
  • Do what you want to do inside the printer.
    
  • When you're done fiddling, undo in reverse order.
    
  
  
• CHECKING TRUE INK LEVELS:
  
  
  • HP's ink-level reporting software tends to say you're running lower on ink than you actually are.
    
  • It's O.K. to print until the cartridge runs dry. Each cartridge has a new print head in it.
    
    
  • To tell how much ink you actually have left:
    Weigh a sample of each cartrige when new, and and again when you've run it completely dry. You can use a postal scale or similar. I use an old beam-balance like those in high-school chemistry labs.
    
    Here are typical numbers I've gotten for the cartriges I use:
    
    - Black, # 51645A (now just "HP # 45 "), 42 ml:
    ------ full: 113 grams (4.0 ounces)
    ------ empty: 69 grams (2.5 ounces)
    
    - Color, # C6578D (now just "HP # 78 "), 19 ml:
    ------ full: 119 grams (4.2 ounces)
    ------ empty: 97 grams (3.4 ounces)
    
    Especially for the black cartridge it's easy to take it out, weigh it, and see how much is left. The difference between full and empty is pretty large.
    
    
  • Hewlett-Packard factory cartridges are high quality but quite expensive.
    Here is a source for ink cartridges from the Original Equipment Manufacturer ("OEM") and refilled/remanufactured, plus refilling kits, for a LOT less:
    
    4inkjets.com - OEM and remanufactured cartridges, refill kits.
    
    The above vendors sometimes have special sales offering reduced or zero shipping costs, free extra cartridges, etc. Take a look to see what's currently available.
    
  
  
• PAPER FEEDING OR JAMMING PROBLEMS:
  
  
  • Slippery rubber "paper-grabber" rollers.
    The "soapy water" fix:
    The best thing I've found is plain old soapy water.
    Take a paper towel, dip it in a bit of water-plus-handsoap, and scrub the rubber rollers that have to pull the paper into the printer. You can leave the soap residue on if you want to.
    Be sure to get all the way around the roller. You'll have to spin it some to get it all.
    This washes off the "glaze" and built-up gunk that makes the roller slick.
    Let it dry, put everything back together, and give it a try.
    
    
  • Try putting the paper in the tray "rougher side" up. Or down, whichever side the rollers grab.
    I had a laserjet that absolutely wouldn't feed paper "smooth side up," but rough side up worked fine.
    It's hard to tell sometimes, you just have to feel both sides and see which feels slightly rougher.
    
    
  • Open the printer as much as you can and look for another piece of paper still stuck in the machine.
    
    
  • Getting at the rollers:
    This varies a lot for different HP models. On my HP LJIIIP I just opened the front cover as if I were going to replace the toner cartridge, and there they were. On the HP P1000 there's an access door in the back. Check your user's manual.
    
  
  
• LUBRICATION:
  
  In general, the print-head slides along two points of contact as it goes back and forth. You need to lubricate both of those surfaces.
  
  • Use grease, not oil. Oil will run off.
    
  • Any light grease will probably work fine. I use Lubriplate, which is a white grease that comes in toothpaste-size tubes. Your local hardware store, auto-supply store, or electronics store will probably have it.
    
  • It's probably best to avoid molybdenum-containing or graphite-containing greases. They may be electrically conductive, and could cause problems if they get onto the electronics. "White" greases don't have this problem.
    
  • Where to grease:
    - Put a few dabs on the round metal rail that the head goes back-and-forth on. Put some on the rail on both sides of the head.
    - The second point of contact varies. Often there's a top rail that the cartridge-carrier will be rubbing against as it goes back and forth. That's the one that's most often missed. Often the surface faces away from the opening and it's hard to see. You may have to put grease on your fingertip and reach back and up to smear some on the surface without being able to see it.
    
  • Avoid getting any grease on the drive belts that pull the head back and forth!
    
  • Now close up the printer and try it. The first few times the printhead goes back and forth it'll spread the grease around. Then any odd scraping or rubbing noises you'd been hearing will likely be gone.
    

4inkjets.com - OEM and remanufactured cartridges, refill kits.