HP LaserJet 4 Service Manual - Page 106

Clearing the TONER LOW Message If the 16 TONER LOW message appears in the control panel display, the toner level in the toner cartridge is getting low. The print becomes lighter and white streaks may appear. (This message means that it is time to replace the toner cartridge). If the control panel Config Menu Toner Low item is set to TONER LOW=ON (or CONT on the LJ4+ and LJ5 printers), the printer continues to print with the 16 TONER LOW message in the control panel display. TONER LOW=ON is the default setting. A Configuration Menu setting TONER LOW=OFF (or STOP on the LJ4+ and LJ 5 printers) is available that causes the printer to go off-line and to stop printing when low toner is detected. If TONER LOW=OFF (or STOP) is selected from the Configuration Menu, you must press [Continue] (or Go on the LJ 5) to resume printing. Use the TONER LOW=OFF (STOP) setting when sharing the printer with other users, or when using MICR cartridges. You can improve the print quality temporarily by redistributing the toner as follows: 1 Remove the toner cartridge. 2 Rotate the toner cartridge about its horizontal axis (i.e., not end over end) to redistribute toner. 3 Reinsert the toner cartridge and press [On Line] (or Go on the LJ5). The 16 TONER LOW message still may appear, but the print quality should improve. If the print remains light, replace the toner cartridge immediately. Install the new cartridge as described in the instructions included with the cartridge. 4-10 Preventive Maintenance