4-6 Phaser 6300/6350 Color Laser Printer Service Manual
Service Diagnostics
Service Diagnostics provides tests for most electro-mechanical components in the 
printer. Service Diagnostics also contains test prints, printer status and some NVRAM 
access. If confronted with an error that requires more than a cursory investigation to 
clear or when directed by a troubleshooting procedure, use Service Diagnostics to 
exercise selected sub-assemblies of parts in the vicinity of the reported error. Tests are 
controlled from the Control Panel and are described in detail in the Appendix. 
The Service Diagnostics Main menu offers the options listed in the following table.
Using Service Diagnostics
The printer’s operating system monitors sensors located throughout the print engine 
and attached options. Sensor signals are used to monitor paper handling and 
mechanical activity along the entire paper path. As a sheet travels along the paper 
path, sensors change state temporarily to indicate the sheet’s presence. If the pattern 
of sensor state changes differs from the expected timing for a particular paper size and 
path, the sensor where the timing difference occurs identifies the error to report.
However, having the error message information doesn’t necessarily pinpoint the 
problem. Sensor signals locate where, but often cannot identify why. Motors, belts, 
gears, solenoids, and numerous other parts are involved in paper transport. The 
Service Diagnostics’ suite of tests and utilities are the best tools available to pinpoint 
the root cause behind the reported error. 
Service Diagnostics Main Menu
Menu Item Test Target
Print Service Menu Map Prints the Service Diagnostics menu map.
General Status Query information about the status, versions, and counts. 
Test Prints Isolate problems with Xerographics and paper handling. 
Motors/Fan Tests These tests exercise each motor or fan. 
Sensor/Switch Test Tests sensor status and operation. 
Clutch Tests Tests clutch function.
Solenoid Tests Tests solenoid function.
Maintenance Clean the IDT rollers in the Imaging Unit.
NVRAM Access Reset PostScript or all NVRAM. 
IP Controller Diagnostics Tests the Image Processor Board.
Exit Exits Service Diagnostics and reboots the printer.