8-104 Phaser 6300/6350 Color Laser Printer Service Manual
Engine Control Board (PL9.1.16)
Caution
Critical printer-specific information is stored in the NVRAM device located on 
the Engine Control Board. You can either save this information to the Image 
Processor Board using the Service Diagnostic Store/Restore utilities or exchange 
the NVRAM devices between the new and old boards. 
1. If the printer is functional, save the NVRAM data using the Service Diagnostic 
utilities before starting disassembly.
Caution
Observe proper ESD procedures when handling any circuit board.
2. Remove the Top Main Cover (page 8-8).
3. Remove the Right Side Cover (page 8-12).
4. Remove the Left Side Cover (page 8-13).
5. Remove the Rear Cover (page 8-16).
6. Remove the Image Processor Board (page 8-98).
7. Remove the Imaging Unit.
Note
Cover the Developer Frame Assembly with paper to avoid damage to the rollers 
and Toner spillage. Also, take care not to allow the unplugged connectors to be 
drawn inside the printer.
8. Push down to release the 2 hooks of the Electrical Cover and remove the cover.
9. Unplug the 3 harnesses on the Engine Control Board accessible from inside the 
Electrical Cover.
10. Remove the screw (metal, 6 mm) that secures the Engine Control Board Bracket 
underneath the Electrical Cover.
11. Disconnect connectors P/J151, P/J141, and P/J3411 connected to the Laser Unit, 
HVPS, and CRUM Reader.
12. Push these harnesses to the clamp located directly beneath the Laser Unit to 
provide slack to extract the Engine Control Board.