Xerox Phaser 840 Service Manual page 262

CAP/WIPE/PURGE (C/W/P) CHECK LIST
1. Verify C/W/P belt alignment.
Is the C/W/P out of alignment?
YES: Perform C/W/P belt alignment procedures. Go to step 2.
2. Print Service Test Print 2: Weak and Missing Jets.
Is there color mixing from one row to the next row for the same jet?
YES: Replace C/W/P. New C/W/P may take 6 purges before optimal performance. Repeat Step 2.
3. Visually check the printhead faceplate.
Are there streaks or smudges of wax in the jet area of the printhead?
YES, replace C/W/P. New C/W/P may take 6 purges before optimal performance. Go to Step 2.
4. Visually check the C/W/P wiper gasket.
Is there any separation on the wiper blade, or pitting of the C/W/P gasket?YES
YES, replace C/W/P. New C/W/P may take 6 purges before optimal performance. Go to Step 2.
5. Check the Purge Performance.
5a. Check the vacuum and decay time at the metal pipe using vacuum "T" during front panel CLEAN
cycle.
The peak vacuum at the metal pipe is:_____________
If more than 38 cm Hg (15 in Hg, 7.4 psi) Go to Step 5c.
If less than 38 cm Hg (15 in Hg. 7.4 psi), check the vacuum at the pump side of the air
valve (or outlet of vacuum module) without "T" during front panel CLEAN cycle.
Measured vacuum pump reading_____________
If measured vacuum is 40 cm Hg (15.7 in Hg, 7.7 psi) or more, vacuum pump
(module) is OK, so troubleshoot the following for the source of the vacuum leak:
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Go to Step 5c.
5b. If less than 40 cm Hg (15.7 in Hg, 7.7 psi), set vacuum voltage to 24V (old 340s) or replace the
vacuum pump or module. Go back to Step 5.
5c. Check the time it takes for the vacuum to decay to 0 cm Hg.
Decay time____________
(Decay time for 340,350,360,380 is 3-6 Sec., decay time for Z840, Z850 is 4-6 Sec.)
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246 Phaser 840/850/860/8200 Color Printer - Service Manual
Misaligned CWP due to improper belt alignment.
Improper Head to Drum Gap (340/350/360/380/840 only)
Interference with printhead tilt mechanism.
Plugged or cracked tubing between CWP and air solenoid or vacuum module.
If the decay time is longer than the specified times, check the metal and rubber lines
for ink fouling. If the lines are ok, replace air solenoid (for newer printers, the entire
vacuum module must be replaced as air solenoid is not accessible.)
If the decay time goes to zero suddenly, check the rubber lines for cracks or holes
and replace as necessary. If lines are OK, replace the air solenoid or the vacuum
module.
YES NO
Go to #2
YES NO
Go to #3
YES NO
Go to # 4
NO
Go to # 5