January 2010
2-34
Phaser 7760 Color Laser Printer
004-338, 004-340
Revised
Status Indicator RAP’s
004-338 Interface PWB Fuse F5 Open
Fuse F5 on the Interface PWB is open.
Troubleshooting References
Troubleshooting Procedure
NOTE: No error message will be displayed if Fuse F5 on the Interface PWB opens during the
printing process. After power is cycled, the 004-338 error code should be displayed.
Fuse F5 on the Interface PWB provides circuit protection through the following P/Js. Verify that
there are no short circuits or components that would cause this Fuse to open again if replaced.
• P541, pin A8, pin A9, pin B5
• P543, pin 7, pin 9, pin 11
004-340 Controller RAM Fail or Flash ROM Limit Fail
Engine Control Board (MCU PWB) RAM test failed or limit of Flash ROM or Flash ROM failed.
Troubleshooting References
Troubleshooting Procedure
CAUTION
Careful replacement of the Engine Control Board (MCU PWB) NVRAM is important to avoid
serious machine failure.
Table 1 References
Applicable Parts Parts List Wiring and Plug/Jack References
I/F PWB PL 9.1 Section 7, I/F PWB, Main Motor, LVPS T11 Plug/Jack
Locations - Figure 16
Block Schematics and Wiring Schematics - Chain 13
Table 1 References
Applicable Parts Parts List Wiring and Plug/Jack References
Engine Control Board
(MCU PWB)
PL 13.1 Section, Engine Control Board (MCU PWB) Plug/
Jack Locations - Figure 15
Table 2 Procedure
Step Actions and Questions Yes No
1 1. Cycle power the printer to clear the
error.
2. Did this clear the error?
Complete. Replace the Engine
Control Board
(MCU PWB) (REP
1.2).
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