Inspection - Xerox Phaser 840 Service Manual

Inspection

Rollers: Replace the rollers when you see any of the following defects:
Flat spots
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Out of roundness
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Cracked rubber
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Loss of traction (tackiness) causing pick or feed failures
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Gears: Replace gears that show any signs of wear or breakage. Look for these problems:
Thinned gear teeth.
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Bent or missing gear teeth; check especially where a metal gear drives a plastic
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gear.
Fractured or cracked gears (Oil or incorrect grease on a plastic gear can cause
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the gear to crack.)
Belts: Inspect the belts for wear. There are eight rubber belts in the printer:
A belt from the process motor to the compound gear
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Two belts from the y-axis motor drive
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A belt from the lower paper-feed roller to the upper paper-feed roller
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Two belts on the cap/wipe/purge drive
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An exit-roller drive belt
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A small belt for driving the cap/wipe purge assembly from the cap/wipe/purge
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clutch
Look for these problems:
Loose rubber particles below the belts indicate a worn belt
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Missing teeth in the belts
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Cracking or moderate fraying; a small amount of fraying is inevitable, so look
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for other signs of wear before replacing the belt
Clutches: There are four clutches: the paper-pick roller clutch, the upper-feed-roller
clutch, the maintenance drawer cam clutch and the cap/wipe/purge clutch. Symptoms of a
malfunctioning clutch are the printer not picking paper from the tray or other paper jams.
Also the cap/wipe/purge system could fail. In such cases, replace the clutch. Intermittent
jams are often caused by failing clutches.
6 - 178 Phaser 840/850/860/8200 Color Printer - Service Manual