Xerox M20 - WorkCentre B/W Laser, Service Manual

Page: 210 / 314

December 2006
6-4 WorkCentre M20, 4118, FaxCentre 2218 Family
GP 1
General Procedures and Information
LSU HSYNC TEST CHECK Checks the time of the LSU HSYNC (Horizontal Synch.
Signal).
The time in milliseconds, will be displayed after approx-
imately 10 seconds. NEXT Go to the next test (LSU MOTOR TEST)
2 SENSOR TEST CHECK Monitors the status of the Paper Path Sensors and
Interlock.
‘1’: Active, ‘0’: Inactive
Refer to Table 2 Sensor description for details. EXIT Go to the top level of Engine test mode.
3 SCF MOTOR TEST ON Runs the Second Cassette Feeder (SCF) Motor OFF Stops the SCF Motor
SCF SOLENOID TEST ON Energizes the Second Cassette Feeder (SCF) Sole-
noid (300ms. timeout) OFF De-energizes the SCF Solenoid
SCF EMP/INST CHECK CHECK Checks if the Second Tray is installed. (Monitors the
Second Cassette Feeder (SCF) Paper Empty Sensor) NEXT Go to the next test (SCF MOTOR TEST)
4 OPC FUSE STATE CHECK Checks for a new OPC Fuse. (Compares against previ-
ous known state during warm-up) NEXT Go to the next test (OPC FUSE CHECK)
OPC FUSE CHECK CHECK Displays the current state of the OPC Fuse. NEXT Go to the next test (TONER STATE)
TONER STATE CHECK Displays the Toner status.
This test does not check current toner status. It only
displays the stored value in the SDRAM when the side
cover was last opened or at power on. To update the
stored value in the SDRAM open and close the side
cover. NEXT Go to the next test (TONER LOW CHECK)
TONER LOW CHECK CHECK Checks current toner status NEXT Go to the next test (PAGE COUNTER INC)
PAGE COUNTER INC CHECK Increases the page count by 1 NEXT Go to the next test (AIR TEMP CHECK)
AIR TEMP CHECK CHECK Displays the temperature of current working environ-
ment using ADC values. See below for typical ADC
conversions:
200 = -11C/12F, 178 = 0C/32F, 155 = 10C/50F, 121 =
25C/77F, 73 = 50C/122F NEXT Go to the next test (OPC FUSE STATE)
5 MHV SUPLY 1350V (Not to be used dur-
ing service, manufacturing use only) ON Switches on 1350V to the MHV OFF Switches off the voltage to the MHV
MHV ADC READ CHECK Reads and displays the MHV ADC value. If the ADC
value is between 1 and 254 inclusive, this indicates
that the MHV value is good. If the value is 0 or 255 the
display will read “Over The Range”. This indicates
problems with the toner cartridge or drum cartridge or
their respective contacts. NEXT Go to next test (DEV SUPPLY 450v)
Table 1 Test Map
Test No. Test Items (Description) Setting Description Setting Description