HP 8550 Service Manual - Page 492

The copy has an image covered with dots Unit Printer Cause Step Secondary 1 transfer belt assembly Separ- 2 ation static eliminator Separ- 3 ation staticeliminator bias PCB 4 dc controller PCB Checks Yes/No Action Is the charging roller of the YES secondary transfer belt defective or worn? Replace the secondary transfer charging roller. Is the charging wire of the separation static eliminator broken? YES Are connectors J5600, J5601, and NO J5602 on the separation staticeliminating bias PCB connected securely? Replace the separation static eliminating bias PCB. Is the problem corrected? YES NO Replace the separation static eliminator. Connect them securely. End. Replace the dc controller PCB. The copy has a (positive) ghost image Unit Printer Cause Step Connector 1 wiring Pre- 2 exposure LED assembly/ dc controller PCB Checks Are connector J681 on the preexposure LED assembly, relay connectors J74 and J18, connectors J645 and J647 on the main relay PCB, and connector J227 on the dc controller PCB connected securely? Replace the pre-exposure LED assembly. Is the problem corrected? Yes/No Action NO Connect them securely. YES NO End Replace the dc controller PCB. 490 Chapter 7 - Troubleshooting EN