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Service Guide
63
Testing for a shorted motor
1.
Reinstall the power supply if removed in the previous procedure.
2.
Disconnect the process motor, the Y-axis motor, X-axis motor and the
cap/wipe/purge assembly motor wiring harness.
3.
Turn on the printer again to see if it does not overload now that the
motors are disconnected from the power supply.
If the power supply is functional, move to the following procedure, “Testing
motor and solenoid resistances”.
If the motors and solenoids are not shorted, but the power supply still does not
function, replace the power control board.
Testing motor and solenoid resistances
1.
Turn off the printer and disconnect the power cord.
2.
With a DMM set for measuring resistance, test each motor's windings
for correct resistance (disconnected from the printer). Rotate the
motor's drive shaft slightly while taking the measurement.
Testing the cap/wipe/purge vacuum system
Refer to the topic “Evaluating the printhead and cap/wipe/purge system” on
page 80.
Table 5 Motor and solenoid resistances
Motor or solenoid
Phaser 840 printer
Resistance (approximately)
Phaser 850 printer
Resistance (approximately)
Process motor
2.9 ohms +/-15% (Difficult to
measure due to variability at the
brush/commutator interface.)
4.3 ohms +/-15% (Difficult to
measure due to variability at the
brush/commutator interface.)
Y-axis motor
1.4ohms +/- 15% (Difficult to
measure due to variability at the
brush/commutator interface.)
1.4ohms +/- 15% (Difficult to
measure due to variability at the
brush/commutator interface.)
X-axis motor
12.5 ohms/phase (red-to-yellow
and blue-to-orange
12.5 ohms/phase (red-to-yellow
and blue-to-orange
Paper-feed motor
1.5 +/- 20% ohms/phase
1.5 +/- 20% ohms/phase
Maintenance drawer
camshaft electric
clutch
186 ohms +/- 15%
132 ohms +/- 15%
Paper-pick electric
clutch
186 ohms +/- 15%
186 ohms +/- 15%
Cap/wipe/purge and
feed clutch
125 ohms +/- 12%
124 ohms +/- 5%
Transfix cam solenoid
108 ohms +/- 10%
108 ohms +/- 10%
Summary of Contents for Phaser 840
Page 11: ...xii Phaser 840 and 850 Color Printers ...
Page 65: ...54 Phaser 840 and 850 Color Printers ...
Page 101: ...90 Phaser 840 and 850 Color Printers ...
Page 125: ...114 Phaser 840 and 850 Color Printers ...
Page 134: ...Service Guide 123 Clearing PostScript NVRAM menu item ...
Page 135: ...124 Phaser 840 and 850 Color Printers ...
Page 166: ...Service Guide 155 Figure 1 Cabinet FRUs 7 5 6 8 1 2 4 0388 21 3 9 9 ...
Page 170: ...Service Guide 159 Figure 3 Paper path FRUs 0388 80 2 1 5 11 10 9 12 6 4 3 7 13 8 11a 11b ...
Page 172: ...Service Guide 161 Figure 4 Motor and fan FRUs 0388 14 7 4 3 5 6 2 1 ...
Page 174: ...Service Guide 163 Figure 5 Circuit board FRUs 4 3 5 2 1 9 7 6 8 10 11 13 0388 81 12 7a ...
Page 176: ...Service Guide 165 Figure 6 Solenoid and clutch FRUs 4 5 3 2 1 0388 23 ...
Page 182: ...Service Guide 171 Figure 9 High capacity PaperTray 0388 65a 1 2 ...