M-7
BD failure
Possible cause
Step
Check
Result
Remedy
Harness
connection
failure
1
Is the connection of connector P2
on the panel sensor PCB correct?
No
Connect it securely.
M-8
Scanner failure
Possible cause
Step
Check
Result
Remedy
Harness
connection
failure
1
Is the connection of the scanner
motor connector and connector P3
on the panel sensor PCB correct?
No
Connect the
connectors securely.
Power supply
input
2
Is the voltage between pins 1 (+24
VDC) and 2 (GND) of connector P3
on the panel sensor PCB measured
24 VDC?
No
Check if +24 VDC is
supplied between pins
1 (+24 VDC) and 3
(GND) of connector
P4 on the panel
sensor PCB.
If not, check the power
supply input.
Yes
Replace the scanner
unit.
Summary of Contents for HL-720
Page 1: ...SERVICE MANUAL MODEL HL 720 730 730Plus R LASER PRINTER ...
Page 36: ...II 19 1 3 10 Engine I O HL 720 Fig 2 21 shows the engine interface circuit Fig 2 21 ...
Page 37: ...II 20 HL 730 730Plus Fig 2 22 shows the engine interface circuit Fig 2 22 ...
Page 61: ... Fig 3 18 2 4 1 1 1 ...
Page 92: ...SERVICE MANUAL MODEL HL 760 R LASER PRINTER ...
Page 109: ...II 8 1 3 4 DRAM Two 4M bit DRAMs x 16bits are used as the RAM Fig 2 6 ...
Page 113: ...II 12 1 3 10 Engine I O Fig 2 12 shows the engine interface circuit Fig 2 12 ...
Page 114: ...II 13 1 3 11 Paper Feed Motor Drive Circuit Fig 2 13 ...
Page 133: ...Appendix 2 Main PCB Circuit Diagram 1 3 CODE UK3227000 B48K272CIR 1 3 NAME ...
Page 134: ...Appendix 3 Main PCB Circuit Diagram 2 3 CODE UK3227000 B48K272CIR 2 3 NAME ...
Page 135: ...CODE UK3227000 B48K272CIR 3 3 NAME Appendix 4 Main PCB Circuit Diagram 3 3 ...