Lexmark C720 Service Manual - Page 141

5024-001 990-Transfer Drum Encoder Sensor (HPSEN) Service Check FRU 1 Transfer Drum 2 • Transfer Drum Encoder Sensor (HPSEN) • IOD1 P.W.B. Board • Main Engine (MCTL P.W.B.) Board 3 Low Voltage Power Supply (LVPS) Action Check the OPC belt cartridge for proper installation. The transfer drum should rotate with little resistance. If the transfer drum does not rotate lightly or the encoder plate is damaged, replace the transfer drum. Ensure connectors DCN4 on the IOD1 board and the transfer drum encoder sensor (HPSN) are correctly connected. Check for +5V between DCN4-1 and DCN1-3. • If there is +5V, replace the transfer drum encoder sensor (HPSEN) • Check for +5V between DCN2-1 and DCN2-4. • If the voltage is +5V, replace the IOD1 P.W.B. board. • If the problem still exists, replace the main engine (MCTL P.W.B.) board. If there is less than +5V between DCN2-1 and DCN2-4, replace the low voltage power supply (LVPS). Diagnostic Information 2-61