Service manual

6-8 DECcolorwriter 1000
6 Troubleshooting
Testing motor resistances
With a VOM set for measuring resistance, test each motor's windings for its correct
resistance. Rotate the motor's drive shaft slightly while taking the measurement.
Media jams and the paper path
Jams fall into the following four categories:
n Media-based problems
n Paper-picking errors
n Paper-clamping errors
n Paper-ejecting errors
Media-based problems
1. Check that the correct type of media is being used. For plain-paper printing,
the customer should be using a quality plain paper (like that used in a laser
printer) with the Plain Paper Transfer Roll. When using coated paper with the
3-Color Transfer Roll, be sure that the coated side of the paper faces up in the
tray.
Fanning perforated media eliminates its tendency to double-pick due to the
perforations interlocking with neighboring sheets.
2. Inspect the paper for bent, torn or folded corners.
Required tools
n #1 POSIDRIV® screwdriver
n VOM
Table 6-1. Motor and solenoid resistances
Motor or solenoid Resistance (approximately)
Paper-feed motor (white wire is pin 1) 60 ohms between pins 3, 4 and 5, 6
30 ohms between pins 1, 3 and 1, 4
30 ohms between pins 2, 5 and 2, 6
Drum motor (white wire is pin 1) 30 ohms between pins 4, 5 and 5, 6
15 ohms between pins 1, 5 and 1, 6
15 ohms between pins 2, 3 and 2, 4
Transfer roll feed motor 45 ohms
Thermal head lift motor 35 ohms
Solenoids 150 ohms
Required tools
n #1 POSIDRIV® screwdriver
n VOM