Service manual

7-4 DECcolorwriter 1000
7 Cleaning and Maintenance
Gears: Replace gears that show any signs of wear or breakage. Look for these
problems:
n Thinned gear teeth.
n Bent or missing gear teeth; check especially where a metal gear drives a
plastic gear.
n Fractured or cracked gears.
Belts: Inspect the belts for wear. There are three rubber belts in the printer: a belt from
the head motor to the head lift cam, a belt from the drum motor to the drum pulley, and a
belt from the lower eject roller to the upper eject roller. Look for these problems:
n Loose rubber particles below the belts indicate a worn belt.
n Missing teeth in the belts.
n Cracking or moderate fraying; a small amount of fraying is inevitable, so look
for other signs of wear before replacing the belt.
Clutches: There are two clutches: the paper-pick roller clutch and the alignment roller
clutch. Symptoms of a malfunctioning clutch are the printer not picking paper from the
tray or random skewing of the print. In such cases disassemble and check inside the
suspect clutch for a lack of grease, a broken spring, or worn gear teeth.
Replacements
Drum belt: Replace the drum belt after 20,000 prints.
Torque limiter: Replace the transfer roll torque limiter after 20,000 prints.