Craden Peripherals DP8 technical manual Defective Sensor, No Document Motion, No Carriage Motion

5.6.4 Defective Sensor

All sensors transmit infrared light and sense light reflected by a document, gap roller or cabinet. The sensors are automatically re-calibrated each time the printer powers on. First check that the flex cable is firmly seated in the connector on the Sensor PCB.

Press 9 0 FUNCT to run diagnostics and display “SENSORS” and the letters LFBMRCE. L is the left home carriage sensor; F and B are the front and back document sensors, M and R are the middle and right skew sensors, C is the cabinet open sensor and E is the document edge sensor. The cabinet open sensor is mounted on the main PCB and looks through a slot in the rear panel heat sink. The document edge sensor is mounted on the carriage and “looks” down toward the platen. All other sensors are mounted on the multi-sensor PCB (See picture in 5.1.3). Any sensor that is covered will have its corresponding indicator erased. Each sensor may be activated to check for proper operation. Press A↑ to conclude this test. Place an object in any sensor’s light path to remove the corresponding sensor letter from the display. Press ENTER to return to READY status.

Symptom	Condition	Remedy
Rollers run continuously before a	Front sensor light path is blocked	Clear front sensor light path of
document is inserted and no “F”	by paper, paper dust, or a bent	paper scraps or blow sensor area
on display during 90 FUNCT.	input guide. A sensor may be bent	with compressed air.
	out of position.
Rollers run continuously after a	Back sensor light path is blocked	Clear back sensor light path of
document is ejected and no “B” on	by paper, paper dust, or a bent	paper scraps or blow sensor area
display during 90 FUNCT.	input guide. Sensor may be bent	with compressed air.
	out of position.
Carriage drives into the left side of	94 FUNCT parameters are	Check 94 FUNCT parameters
the printer.	incorrect	against label under the cabinet
		behind the alphanumeric display.
	Disconnected sensor cable	Reinsert sensor cable
	Defective left “home” sensor.	Replace multi-sensor PCB
Display reads “Cover Open” even	Cover sensor cannot “see”	Override cover sensor using 99
when cabinet is closed	reflective dot on inside of cabinet.	FUNCT (3.5.3) or replace
		reflective foil dot

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 3.5.1).

3.Check that the drive belts are on their pulleys and the pulleys are tight on their shafts.

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 6 ohms resistance between pins 1 and 2 and between 3 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.

5.6.6No Carriage Motion

If the carriage will not move at power-up (CARRIAGE FAULT) or after a document is inserted:

1.Check that the flex cable is firmly seated in the connector on the Sensor PCB.

2.Check that the shipping blocks fastening the carriage have been removed.

3.Press ENTER if configured for PRINTING AFTER ENTER KEY (see 3.5.1).

4.Check that the motor cable is seated onto J5 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 6 ohms resistance between pins 1 and 3 and between 4 and 5 of the motor connector. If not, replace the motor (see 5.5.10).

7.Repair or replace the main PCB with a bad U6 or U7 driver circuit.

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