Code: 11
Display:
11 Paper Out
Description:
Paper tray empty or not seated correctly. A buildup of toner on the edges of the tray which slide into the printer can sometimes cause problems. Take a sharp tool, like a razor blade and scrape the buildup off these edges.
Sensor Arm Stuck or Broken - check for free movement of the sensor arm. Sensor flag can get knocked out of place when a paper jam occurs and the tray is pulled out abruptly. Most times this can simply be reinstalled. If it's broken, you will need to replace the sensor flag.
Defective Tray Size Sensing or Configuration - Most trays have tabs which depress a series of switches when installed. Verify that the tabs aren't damaged and that the tray switches located in the printer are not damaged. You can depress these by hand and hear them click. Occasionally the contact for the micro switch will get bent and will have to be replaced. Also verify the configuration through the menus on the printer.
Defective Paper Control Sensor PCB - These do fail and will need to be replaced.
Code: 12
Display:
12 Printer Open
Description:
Top cover open or a broken tab on the cover assembly. On rare occasions a defective paper control assembly or actuator can cause this problem. Verify the tab on the cover is not broken.
Code: 13
Display:
13 Paper Jam
Description:
Check the paper, make sure it meets the paper specifications for your printer. Tractor feed paper with the edges ripped off doesn't seem to work very well. Extremely heavy or thick paper is also a problem. Check the hp paper specification guide for more info. Be careful with labels, use only labels designed to take the heat generated by the fuser assembly. Regular labels my "ooze" adhesive as they pass through the fuser assembly and literally gum up the works! Also check for any partially peeled labels, this can be a disaster if they come off inside the printer.
Is the paper size correct? Is the software set for the size you're using? Is the menu set for the size you're using? Check these items. If the software tells the printer to expect a different size (legal, A4, COM10) than the tray available, you will get an error. This can happen when printing a FAX document formatted for A4 size paper.
You could also have a defective or dirty exit sensor. Replace or clean as needed.
Make sure the paper cassettes are installed correctly. A buildup of toner on the edges of the tray which slide into the printer can sometimes cause problems. Take a sharp tool, like a razor blade and scrape the buildup off these edges.
Bad drive gears. Again on the LJII/III we are starting to see more and more failures of the gear drive assembly. A broken tooth on one gear is all it takes. Replace this as an assembly.
Listen for the motor operation, make sure it's operational. If not replace the motor or drive circuit as required.
Code: 14
Display:
14 No EP Cartridge
Description:
On the 4V/4MV check the toner cartridge micro switch on the High Voltage PCB - SW501.
Also on the 4V/4MV check the door open sensor (PS402) on the terminal board located under the transfer roller.
Can also be caused by a defective DC controller. Pretty rare though.
Code: 16
Display:
16 Toner Low
Description:
Toner cartridge is empty or toner in cartridge is not distributed evenly. Gently shake the toner cartridge both from side to side and from front to back. This can generally get you 100 or so more pages.
Bad or dirty cartridge contacts. Look for the conductive contacts on the cartridge and the corresponding contacts in the printer and make sure they are clean and free of contaminants.
Code: 18
Display:
18 MIO Not Ready
Description:
The printer is not connected to a LAN when it's expecting to see a LAN. Terminate the port on the printer with a BNC T and two 50 ohm termination's.
The MIO card is defective or maybe just not seated correctly. Remove the card and reseat it, try swapping with a know good card from another printer. Replace if necessary.
Code: 20
Display:
20 Memory Overflow
Description:
A large print job has exceeded the memory capacity of the printer. Verify that the SIMMS or memory cards are seated. Add more memory or simplify the print job.
Code: 21
Display:
21 Print Overrun
Description:
The print job is to complex. Simplify the job by removing font changes etc.
The print job is to complex, enable page protect from the control panel and from the software. You may need additional memory.

Code: 22
Display:
22 Error I/O
Description:
Config Error/ Par I/O Error/MIO Error
I/O configuration for the computer or printer is incorrect. Configure is properly.
Check I/O Cable, it could be the wrong cable or damaged.
How about the I/O port - damaged, seated properly, pins not bent?
The computer and printer aren't talking because of improper signal protocols. Could be a bad cable or loose connection or just a poor quality cable. Reseat the cable and use only high quality IEEE 1284 compliant cables.
Code: 23
Display:
23 I/O Not Ready
Description:
The I/O card is not accepting data. May not be connected - check cabling - or it may be defective. Reseat the card and if available, swap with a known working card. Watch the termination's on the network cabling.
Code: 24
Display:
24 Job Memory Full
Description:
The print job is too complex to be processed. Laser printers are page printers and require the entire page to be processed before beginning to print. Simplify the print job by removing font changes and/or graphics. Add more memory.
Code: 30
Display:
30
Description:
An I/O time-out or a prompt for user interaction like a manual feed has been exceeded. Check the I/O connections and make sure the proper media is being used.
This is an unexpected PostScript firmware error. Reseat the PostScript SIMM and/or replace it
PCL file was sent to the printer while in PostScript mode or the PostScript file contains bad data, or you have experienced and application error (crash). You need to check the configuration of your printer and drivers, reset the printer, try issuing an initialization command from within the application. May need to reload your PostScript print driver file.
Code: 40
Display:
40
Description:
Make sure computer and printer are set to the same baud rates. Reset as needed.
Check the MIO card, remove, clean contacts, reinstall. Replace if defective
An abnormal connection break may have occurred during data transfer - Press Continue or Go to clear this error message.
Code: 43
Display:
43
Description:
This indicates a communication problem between the formatter PCA and an optional interface installed (such as a network card). Remove and reseat the optional interface card. If the problem continues, remove the optional interface card and set the printer for standard parallel interface by taking off-line and holding down "Menu" key for 5-10 seconds. Scroll through items until "I/O =" appears and use the /- key to display parallel and the enter key to select. Then put the printer back online and send a test job from the host computer via the parallel cable. If this is successful, you have a problem with the optional I/O card and should replace it or reset it.
Code: 50
Display:
50 Fuser Error
Description:
defective heater, termistor, termoswich, triac
Code: 51
Display:
51 Loss of
beam detect
Description:
Improperly seated toner cartridge - remove and reinstall
Laser shutter blocked or damaged
Damaged fiber optic cable
Defective Laser PCA - replace
Faulty Laser Scanner Cable Connectors - Remove and Reseat connectors
Defective Laser Scanner Assembly - Replace

Code: 52
Display:
52
Description:
incorrect scanner speed and is generally the same as an error 51.
Code: 55
Display:
55
Description:
On IIISi/4Si Printers this is due to the DC controller not receiving the proper information upon startup. Check the connectors on the DC controller and power supply. If you don't hear the motor immediately and you don't have a paper jam, change the power supply.
Code: 57
Display:
57
Description:
Main motor problem, check gear train for binding. Check connections to DC controller - replace main motor
Check gear train for binding. Replace main motor
Code: 58
Display:
58
Description:
Check the fan cable - reseat cable or replace fan
Defective DC controller board - replace
Code: 59
Display:
59 Add Memory
Description:
Not enough memory for PostScript option. Verify SIMM's are seated properly, replace any defective
Code: 79
Display:
79
Description:
Software/drivers, Memory PCA's, Font-Macro-Personality Cartridges, option I/O Cards. Defective toner cartridge in the Laserjet 4 Plus only. Remove any accessories (font cartridges, memory PCA's, SIMMs, etc.) plugged into the formatter card and try again. If the problem persists and is application specific, verify proper setup with application vendor.
Defective Formatter PCA - Replace with known operational board and try again.
Code: 80
Display:
80
Description:
Improper MIO connection - look at pins on formatter MIO connection
Defective MIO Card - Replace card
Defective Formatter Card - Replace card
Code: 89
Display:
89
Description:
The PostScript ROM's have bent or broken pins inspect the pins and reseat if necessary
Check to see that the ROM SIMM's are in the proper location and oriented properly
This can also be a temporay error, try power cycling the printer
The PostScript ROM's/SIMM are defective