Xerox 2135DX - Phaser Color Laser Printer, Service Manual

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Service Guide 35
Ensuring the +5 VDC loop is complete
The +5 voltage from low-voltage power supply is routed out of the power supply
connector CN1, via a wiring harness, to the POWER connector the engine
controller board, through surface-mount fuse F6, out the engine controller board
via the ribbon cable OPTN to the toner sensor board. The +5V is then routed back
out the toner sensor board through its power supply harness to the low-voltage
power supply connector CN 2.
Upon power-up, if the low-voltage power supply does not detect the return of the
+5 VDC, then the power supply will immediately shut-down. You may see the
CPU fan “bump” or the engine board LED (LED2) flash. To troubleshoot the loop:
1.
Test surface-mount fuse F6 for continuity. It is located on the upper-right
corner of the engine controller board next to the REG connector. If the fuse
is opened, replace the engine controller board.
2.
Inspect the two power wiring harnesses and the ribbon cable that carry the
+5 VDC loop. Ensure they are properly connected. The wiring harness
leading form the toner sensor board to the power supply features an
interconnect next to the rear hinge. Ensure it is properly connected.
Door safety interlock switches
0725-63
Top Cover
Open Switch
Front Cover
Open Switch