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For any of the five (document, carriage left home and cover open) slotted optical sensors:
1. Check that the slot is free of debris and paper dust. In the case of the document sensors, check that it is
aligned with the holes in the chutes.
2. Check that sensor connector is firmly seated on J5 of the main PCB.
3. Remove the sensor connector cover and check that the respective sensor wires are seated in their
individual connector slots.
4. Replace the sensor (see 5.5.6 or 5.5.7) or U7 (DP6) or U8 (DP7) on the main PCB.
5.6.5 No Document Motion
If a document will not advance upon insertion:
1. Press EJECT if the previous document was manually removed without an eject command.
2. Press
A if configured for DOCUMENT INSERT WITH
A KEY (see 3.6.1).
3. Check that the drive belts are on their pulleys and the pulleys are tight on their shafts.
4. Check for a good 0.75A fuse in F1 on the main PCB.
5. Check that the motor cable is seated onto J3 of the main PCB.
6. Remove the connector cover and check that the four motor leads are seated in their individual connector
slots.
7. Measure about 3 ohms resistance between pins 1 and 2 and between 3 and 5 of the motor connector. If
not, replace the motor (see 5.5.13).
8. Repair or replace the main PCB with a bad U3 or U4 driver circuit.
5.6.6 No Carriage Motion
If the carriage will not move at power-up (CARRIAGE FAULT) or after a document is inserted:
1. Check that the orange shipping strap fastening the carriage has been removed so the carriage can move
from left to right.
2. Press ENTER if configured for PRINTING AFTER ENTER KEY (see 3.6.1).
3. Check for a good 0.75A fuse in F1 on the main PCB.
4. Check that the motor cable is seated onto J2 of the main PCB.
5. Remove the connector cover and check that the four motor leads are seated in their individual connector
slots.
6. Measure about 3 ohms resistance between pins 1 and 3 and between 4 and 5 of the motor connector. If
not, replace the motor (see 5.5.11).
7. Repair or replace the main PCB with a bad U1 or U2 driver circuit.
5.6.7 No Print or Light Print
If there is no printhead noise when the carriage traverses a document:
1. Check that the printhead is plugged into the carriage flex cable(s).
2. Check that the flex cable(s) are plugged into the main PCB.
3. Replace timers U14&15 (DP6) or U17&18 (DP7) or MOSFET Q3 on the main PCB.
4. Repair or replace the main PCB with a bad driver circuit.
If there is printhead noise but there is no print or light print:
1. Correctly install the ribbon cartridge (see 3.3) or replace it if worn out.
2. Remove the cartridge and check for jammed ribbon.
3. Check that the cartridge knob rotates as the carriage traverses.
4. Check for a displaced or upside down ribbon shield
5. Check that QUIET MODE is turned off under 92 FUNCT.
6. If a DP7, check the NORMAL and CQ DARKNESS parameters (see 3.6.3)
7. Check the printhead gap (see 5.4.1).
8. Clean the printhead (see 5.1.4).
