HP 8550 Service Manual - Page 519

E812 (printer) This error occurs when the intermediate transfer drum (ITD) home position is not detected within a specific time (about 10 seconds). Cause Intermediate transfer drum (ITD), Density sensor Step 1 Checks Is the intermediate transfer drum (ITD) set in the printer properly? Y/N NO YES Action Set the drum properly, and turn the power off and then on. See "E020 (printer)" on page 498. E813 (printer) This error occurs when both the upper fusing roller temperature detection signal (FXTHU) and the lower fusing roller temperature detection signal (FXTHL) indicate -10° C or less. Cause Fusing assembly Step 1 Checks Y/N Is the fusing assembly set in the NO printer properly? Connector 2 (fusing assembly) Connector (dc 3 controller PCB) Is connector J26 of the fusing NO assembly connected securely? Is connector J222 on the dc controller PCB connected securely? NO YES Action Set the fusing assembly properly, and turn the power off and then on. Connect the connector securely. Connect the connector. Replace the dc controller PCB. E814 (printer) A specific number of copies have been counted after the photosensitive drum end of life warning has been issued. Cause Step Drum cartridge 1 Checks Y/N Replace the drum cartridge. Is the YES problem corrected? NO Action End. Replace the dc controller PCB. EN Copy module troubleshooting 517