NOTE: You will need an ohm-meter for this procedure.
PROBLEM DESCRIPTION: Printer has no line feed, carriage movement, or
dot fire because the 5 Amp fuse is blown. After the fuse is replaced
and Self Test is tried, the fuse blows again.
CAUSE: Probably either the line feed or carriage stepper motor has
shorted a winding, causing the fuse to blow.
CURE: TO CHECK THE LINE FEED MOTOR (DMP and IW have same stepper motors)
1. Remove the logic PCB, disconnect plug CN1 (line feed stepper
motor connector for both DMP and ImageWriter).
2. Measure for approximately 65 ohms between the following pins
with an ohm-meter: 6 to 2, 6 to 4, 5 to 1, and 5 to 3.
3. If any measurement is significantly less than 65 ohms, that
probably means that a winding is shorted in the line feed
motor and it should be replaced. (The DMP's line feed
stepper motor is not listed as a replacement part. However,
the line feed stepper motor for the ImageWriter will also
work for the DMP. ImageWriter line feed stepper motor P/N
is 699-0109).
TO CHECK THE CARRIAGE MOTOR
1. Remove the logic PCB, disconnect plug CN3 (Carriage stepper
motor connector for both DMP and ImageWriter).
2. Measure for approximately 10 ohms between the following pins
with an ohm-meter: 6 to 2, 6 to 4, 5 to 1, and 5 to 3.
3. If any measurement is significantly less than 10 ohms, that
probably means that a winding is shorted in the line feed
motor and it should be replaced.
IF BOTH STEPPER MOTORS CHECK OUT
There is probably a short on the main PCB so replace it.
If this cure does not resolve the problem, go back to the Word Search
screen and search on the product's name and HTS and GTS to obtain a
General Troubleshooting procedure.