HP LaserJet 4 Service Manual - Page 276

Table 7-25 Vertical Dark Streaks Possible Cause Dirty Primary Charge roller. Bad Toner Cartridge. Incompatible media. During media manufacture, inks, or other finishing processes may interfere with the electro-photographic or fusing process. Action Change the Toner Cartridge. Replace the Toner Cartridge. Change type of media. Table 7-26 Large Print Voids Possible Cause Defective laser shutter. EP Cartridge Support damaged, improperly positioned, or missing. Bad transparencies. Transparencies exhibit this problem if they are not designed for proper toner adhesion. Bad paper lot. The surface of the paper may be too smooth for proper toner adhesion. Poor fusing. Toner may not be fused properly to the media. Print image fusing may not occur correctly. Wet paper. The paper may be damp. Transfer roller is dirty. Action Check the laser shutter for free operation when inserting the EP Toner Cartridge. Refer to item 4 in Figure 8-4a. Guide must be installed properly above the EP Cartridge, between the laser shutter opening and the fuser stop plate. Use Hewlett-Packard-approved transparencies (refer to the HP LaserJet Family Paper Specifications Guide). Try a known good paper from a reliable source (refer to the HP LaserJet Family Paper Specifications Guide). Try a known good paper from a reliable source (refer to the HP LaserJet Family Paper Specifications Guide). Replace Fuser Assembly (see Figure 7-11 for location). Try a new batch of paper. Store the paper in a dry area. Replace the transfer roller. 7-46 Troubleshooting