HP 8550 Service Manual - Page 505

E100 (printer) The laser of the scanner unit is faulty. This error occurs when the dc controller PCB detects DBERR for 2.5 seconds or longer after the scanner motor has rotated at a specific speed. Cause Step Connector (laser 1 driver signal line) Connectors (BD 2 line) Laser scanner 3 unit Checks Y/N Are connector J1001 on the laser NO driver PCB and connector J205 on the dc controller PCB connected securely? Are connector J2 on the BD PCB, NO relay connector J40, and connector J211 on the dc controller PCB connected securely? Is the voltage between connectors YES J211-1 (+5 V) on the dc controller NO PCB and J211-3 (GND) 5 V immediately after the copier is turned on? Action Connect the connectors securely. Connect the connectors securely. Replace the laser scanner unit. Replace the dc controller PCB. E110 (printer) This error occurs when the scanner motor fails to reach a specific revolution within 10 seconds after it has started to rotate. This error can also occur when the BC PCB detects an error within 2.5 seconds after the scanner motor has started to rotate. Cause Connector Step 1 Laser scanner 2 motor Checks Y/N Are connector J901 on the laser NO scanner motor PC, relay connector J40, and connector J211 on the dc controller PCB connected securely? Does the voltage between YES connectors J211-7 (SCND) on the dc controller PCB and J211-6 NO (GND) change from 0 to 17 V or more when the copier is turned on? Action Connect the connectors securely. Replace the laser scanner motor. Replace the dc controller PCB. EN Copy module troubleshooting 503