HP 8000dn Service Manual - Page 429

Table 7-20. Bubble Print Possible Cause Recommended Action 1. Photosensitive drum inside toner cartridge is not grounded. 1. Check for proper mounting of the High Voltage Power Supply (HVPW) and the HVPS ground contacts on the toner cartridge. 2. Check for proper seating of toner cartridge. 3. Replace the toner cartridge. 2. High Voltage Power Supply is defective. Replace the High Voltage Power Supply. See "Power Supply, High Voltage (HVPS)" on page 205 for instructions. 3. Toner cartridge is leaking. Replace the toner cartridge. 4. Paper does not meet specifications. The moisture content, conductivity, or surface finish may not work correctly with the electrophotographic process. Try a different paper lot (see HP LaserJet Printer Family Paper Specifications Guide). Table 7-21. White Stripes Parallel to Path Possible Cause Recommended Action 1. Toner cartridge is nearly empty. This can cause uneven toner distribution. Remove the toner cartridge, and shake it gently. The cartridge will soon require replacement. 2. Toner cartridge has been exposed to too much light. Store the toner cartridge in a darkened environment for several days. This may restore the photosensitive potential. EN Image Quality 405