Verifying Print Engine Operation By Printing A Built In Page; Verifying Power Supply Operation; Measuring Power Supply Voltages - Xerox Phaser 840 Service Manual

Verifying print engine operation by printing a built
in page.
If not already on, turn on the printer. If the printer does not begin initializing, go to the
1.
topic, "Measuring power supply voltages".
Once the Power light is on (not blinking) and the front panel displays Ready to
2.
Print it is now possible to print any built-in pages.
If the printer prints the Page, the print engine is working correctly. If the printer does
3.
not print the Page, then a problem exists with the print engine.

Verifying power supply operation

Required tools
TORX T-20 screwdriver
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Digital multi-meter (DMM)
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The power supply is divided into two sections: the AC section used for heaters and the
DC section for control logic, printhead drivers and motors. Verifying the power supply
involves three steps:
Checking for proper AC voltage.
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Inspecting the power supply fuses.
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Testing for a shorted motor or solenoid driver, which shuts down the power
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supply.
See SF 156 ( Phaser 840 only).
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Measuring power supply voltages

AC line voltages are present on the power supply and possibly in
Warning
the printer, via the heaters, while the printer is plugged into an AC
outlet, even if the power switch is off.
Turn off the printer and unplug it from its power outlet.
1.
AC Input: With a DMM set to measure AC voltages, measure the power being
2.
supplied to the printer; it should measure between 87 to 128 VAC (115 VAC nominal)
or 174 to 250 VAC (220 VAC nominal).
Proceed to the step, "Inspecting the power supply fuses" below.
3.
If a heater shorts, F2 or F3 opens. The power supply does NOT shut down;
however, a Service Required error code is displayed on the front panel.
Troubleshooting 3 - 81