Xerox Phaser 8560MFP Service Documentation page 239

System Fails to Power Up
The system fails to power up and the PS, PE and the 3.3 V Indicator LEDs are not illuminated.
NOTE: The 3.3 V LED is located inside the Electronics Module. View the LED through the vent
holes close to the Power Switch.
Use caution around motors, pulleys and live AC connections when working with the system
covers off.
1. System is not receiving proper AC.
a. Inspect the power cord.
b. Verify AC outlet voltage and current capacities are within specifications. The use of
power strips and extension cords is not recommended.
c. If necessary, move the system to a different outlet and retest.
2. Disconnect the Scanner Assembly.
3. Transient on AC line tripped protective circuitry in system power supply. Cycle power to
system to reset protective circuits in power supply.
4. Short circuit on 3.3 V power supply within the Electronics Module. ESD damage to the
system may occur if static electricity is discharged to system electronics.
a. With Power Cord connected, touch the metal Electronics Module to discharge any
static electricity.
b. Turn off system and wait 30 seconds for power supply capacitors to discharge. Dam-
age to circuits within the Electronics Module may occur if the power supply capaci-
tors are not allowed to fully discharge.
c. Unplug power cord and remove system's covers.
d. Unplug the following Electronics Module connectors: This step removes all other cir-
cuits so the Electronics Module can be tested alone.
• Power Control to I/O board (J10)
• Right Side Harness (J9)
• Preheater Lift Solenoid (P/J202)
• Head Tilt Solenoid (P/J208)
• Printhead data (J3)
• Wave Amp signal (J16)
• Left Side Harness (J17)
• Y-Axis Motor (J18)
e. Plug in the power cord and turn the system on.
f. If the PE and PS indicators do not flash momentarily, the short is inside the Electron-
ics Module. Replace the Electronics Module and retest the system. If PE and PS
indicators flash, continue with debug.
g. Connect all harnesses removed.
h. Reassemble the system and retest.
5. Short circuit on 3.3 V power supply within the I/O board.
a. Follow all procedures from Step 3 before proceeding with these steps. The I/O board
needs to be isolated from other systems in the system to be effectively tested.
Initial Issue
Phaser 8510/8560MFP Multifunction Product
CAUTION
b. Turn off system and wait 30 seconds for power supply capacitors to discharge. Dam-
age to circuits within the Electronics Module may occur if the power supply capaci-
tors are not allowed to fully.
c. Connect the Power Control cable to the I/O Board connector (J800). This connects
the I/O Board to the working Electronics Module - nothing else is connected.
d. Turn on power to the system.
6. If the PE and PS LEDs do not flash momentarily, the short is on the I/O board or related
cabling. Skip the rest of this section if the PE and PS LEDs flash, because the problem is
elsewhere in the system.
a. Verify the short is on the I/O Board using an ohmmeter to check the resistance on
J270, pin 1 to ground. Resistance of less than 1K ohm indicates a problem.
b. To isolate problem to I/O board or related cabling, unplug all I/O board connectors.
• I/O Power Control (J840)
• Waste Tray Sensor (J110)
• Stripper Solenoid (J250)
• Paper Tray Sense (J610)
• Front Door Interlock (J600)
• Ink loader Signal (J910)
• Drum Maintenance Kit Detect (J860)
• Drum Thermistor (J870)
• Exit Module (J680)
• Heater Relay Control (J950)
c. Retest the resistance of the I/O board. If the resistance is still less than 1K ohm,
replace the I/O board, reinstall all cables and retest the system.
d. If the I/O board resistance is OK, above 1K, reconnect the I/O Board connectors one
at a time testing the resistance after each connection. At the point resistance falls
below 1K, replace the component just connected.
e. Reassemble the system and retest.
7. Short circuit on 3.3 V power supply within the Printhead.
a. REQURIED: Follow all procedures from 'Short circuit on 3.3 V power supply within
the Electronics Module' before proceeding. The following procedure relies on a work-
ing Electronics Module to determine if the Printhead is causing a short circuit
b. With Power cord Connected, touch the metal Electronics Module to discharge any
static electricity. ESD damage to the system may occur if static electricity is dis-
charged to system electronics.
c. Turn off the system 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. Connect the Printhead Power connector to the Electronics Module (J4).
e. Turn on the system On.
f. If the PE and PS LEDs do not flash momentarily, the short is on the Printhead.
Replace the Printhead and retest the system. Skip the rest of this section if the PE
and PS LEDs flash because the problem is elsewhere in the system.
g. Carefully test the system to ensure damage to the Electronics Module did not occur
due to the shorted Printhead.
h. Reassemble and retest the system.
10/2006
6-37
Diagnostics
Electrical Troubleshooting