Service manual

Chapter 2
2-25
F-2-39
2.3.6.5 Drum Cartridge Presence Detection
0008-1714
This detection is utilized to detect the presence of the drum cartridge.
When the power is turned on or the top cover is closed, the DCNT Board determines the presence or absence of the cartridge by monitoring the following two items:
1) PS71 (ITB HOME POSITION DETECTION signal) outputs "L" periodically.
2) Output results from the TR2 (FEED BACK signal for secondary transfer bias) exceed a specified value.
The DCNT Board determines a cartridge presence only when the three conditions above are satisfied.
When the DCNT Board determines a cartridge absence, it stops the printer engine and notifies an drum cartridge out to the SCNT Board.
DCNT Board
ITB home position
sensor (PS71)
Drum cartridge
ITB HOME POSITION
LED EMISSION signal
(TOPLED)
ITB HOME POSITION
DETECTION signal
(TOPSNS)
Interrupting areas
SCNT Board
Interrupting areas
/SC
(Print command)
TOPSNS
/TOP
VIDEO signals
HP
1
HP
2
HP
3
HP
4
YMC
Bk
Bk
(Mono-color print)
(Full-color print)
HP
1
HP
1
HP
1