Xerox ColorQube 8570 Service Manual page 351

a. Required: Follow all procedures from Step 7.f before proceeding. The following pro-
cedure relies on a working Electronics Module to determine if the Ink Loader is caus-
ing a short circuit.
b. With the power cord connected, touch the metal Electronics Module to discharge
any static electricity. ESD damage to the printer may occur if static electricity is dis-
charged to printer electronics.
c. Turn off the printer and wait 30 seconds for power supply capacitors to discharge.
Damage to circuits within the Electronics Module may occur if the power supply
capacitors are not allowed to fully discharge.
d. Plug in the Power Control to Ink Loader Board connector ( P/J401) to the Electronics
Module. This step adds the Ink loader back to a working Electronics Module, I/O
Board, and Printhead in order to see if the short circuit is also removed.
e. Turn on power to the printer.
f. If the +3.3V SLEEP LED illuminates, the Ink Loader is functional. Skip to Step 10 if
the LED illuminates.
g. If the +3.3V SLEEP LED does not illuminate when the Ink Loader is connected to the
Electronics Module, verify the short is on the Printhead by using an ohmmeter to
check the resistance on P/J401
ohms indicates the Ink Loader or harness is faulty. Replace the Ink Loader
and retest the printer.
h. Plug in all the cables removed during service.
i. Trace through all service steps performed to reattach any cables that were
unplugged during debugging.
j. Attach the printer covers.
k. Perform full test of printer.
10. The short is on the Power Control Right or Power Control Left harness. Reconnect these
harnesses one at a time to determine which harness and/or subsystem is faulty. Repair as
necessary.
Right side harness feeds:
• Drum Encoder
• Process Motor Encoder
Left side harness feeds:
• Electronics Module Fan
• MP Motor Encoder
• HCF option
Xerox Internal Use Only - Revised, 3rd Revision
ColorQube 8570/8870 Service Manual
Pins 1 and 2 to ground. A resistance of less than 50
Printer Fails Power-up: +50V LED Does Not Illuminate
1. Verify that no PEST/POST faults exist, and that the 3.3V LEDs are both illuminated. Pull
out a tray or open a door, verify the +50V LED is not illuminated, and proceed to the next
step.
There are 2 ways to test for +50V functionality.
+50V Diagnostic Method A
a. Entering Service Diagnostics
b. Perform the 50 Volts Control test: Service Diagnostics Menu -> Exercise Menu ->
50 Volts Control.
If R1 = 0, then 50V is functional. If R1=1, then 50V is not functional. The 50V LED illumi-
nation should correspond with this.
+50V Diagnostic Method B
ESD damage to the printer may occur if static electricity is discharged to printer electron-
ics.
a. With the power cord connected, touch the metal Electronics Module to discharge
any static electricity.
(REP 1.8)
b. Turn off the printer and wait 30 seconds for power supply capacitors to discharge.
Damage to circuits within the Electronics Module may occur if the Power Supply
capacitors are not allowed to fully discharge.
c. Turn on the printer.
d. If the +50V LED does not illuminate when the power is turned on and AC is present,
then 50V is not functional.
2. Test the Electronics Module by isolating it from rest of the printer.
a. Unplug power cord and remove printer's covers.
b. Unplug the following Electronics Module connections. This step removes all other
circuits so the Electronics Module can be tested alone.
• Power Control to I/O Board ( P/J402)
• Power Control Right ( P/J701)
• Power Control to Ink Loader Board ( P/J401)
• Printhead Data ( P/J201)
• Wave Amp signal ( P/J901)
• Power Control Left ( P/J302)
• Y-Axis Motor ( P/J301)
c. Tun on printer in idiags mode. Use +50V Control Diagnostic Method A to determine if
50V is functional.
If it is not functional, the Electronics Module is defective. Replace the Electronics
Module (REP 5.1) and proceed to Step 4.b.
If it is functional, the Electronics Module is good. Proceed to the next step.
3. Test the Ink Loader Board.
a. Turn off the printer and wait 30 seconds.
b. Touch the Metal Electronics module to discharge any static electricity.
c. Connect this cable to the Electronics Module.
• Power Control to Ink Loader Board ( P/J401)
October 2012
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Mode.
CAUTION
General Troubleshooting
Electrical Troubleshooting