Xerox 7700DX - Phaser Color Laser Printer Service Manual page 115

Error Chain /
Code Link
124 07-250
Check the voltage on the Tray Module PWB between J 555-1 and ground.
Is the voltage +5VDC?
Yes No
Using the wiring diagrams, check and repair the +5VDC circuits to Tray Module PWB
J555-1.
Check the voltage on the Tray Module PWB between J 555-3 and ground.
Is the voltage +24VDC?
Yes No
Using the wiring diagrams, check and repair the +24VDC circuits to Tray Module
PWB J555-3.
Do all of the resistances indicate continuity?
Yes No
Check for broken wires or bad contacts on connections that are not 1 ohm or
less.
Change the following parts in the order of priority as listed:
1. Interface Board
2. Tray Module Circuit Board
3. Engine Control Board
4. Image Processor Board
Turn off the power. Check for continuity between the following points:
From MCU PWB J407-B10 to Tray Module PWB J541-7.
From MCU PWB J407-B9 to Tray Module PWB J541-9.
From MCU PWB J407-B11 to Tray Module PWB J541-5.
From MCU PWB J407-B12 to Tray Module PWB J541-4.
Change the following parts in the order of priority as listed:
1. Interface Board
2. Tray Module Circuit Board
3. Engine Control Board
4. Image Processor Board
TRAY COMMUNICATION FAILLURE
Phaser 7700 Color Laser Printer Service Manual
Front Panel Message
2-85