CHAPTER 6 TROUBLESHOOTING
6-38
I-3
Completely blank
Possible cause
Step
Check
Result
Remedy
Ground
contacts
Developing bias
contact failure
1
Are the developing bias
contacts between the printer
body and drum unit dirty?
Yes
Clean the electrodes
at both sides.
(4)
Drum unit
2
Are the drum shaft and drum
electrode of the printer body
connected correctly?
Yes
Clean the shaft and
the electrode.
(1)
No
Check the connection
between the shaft and
the electrode.
(1)
Drum unit failure
3
Is the problem solved after
replacing the drum unit?
Yes
Replace the drum
unit.
Toner cartridge
failure
4
Is the problem solved after
replacing the toner cartridge?
Yes
Replace the toner
cartridge with a new
one.
Scanner
harness
connection
failure
5
Is the scanner harness
connected securely?
(Check if there is any play in
the connection.)
No
Reconnect the
connector correctly.
Main PCB failure
6
Are printing signals being input
to the laser unit?
Is the problem solved after
replacing the main PCB?
Yes
Replace the main
PCB.
Laser unit failure
7
Is the scanner interlock lever
damaged?
Yes
Replace the laser unit.
Is the scanner mirror broken or
loose?
No
Replace the high-
voltage power supply
PCB.
Содержание HL-1870N
Страница 15: ...HL 1850 1870N SERVICE MANUAL xiii ...
Страница 77: ...CHAPTER 2 INSTALLATION AND BASIC OPERATION 2 48 ...
Страница 82: ...HL 1850 1870N SERVICE MANUAL 3 5 Fig 3 5 ...
Страница 83: ...CHAPTER 3 THEORY OF OPERATION 3 6 1 3 2 ROM Two 64 Mbits ROMs x 16 bit are fitted Fig 3 6 HL 1850 HL 1870N ...
Страница 85: ...CHAPTER 3 THEORY OF OPERATION 3 8 1 3 4 SDRAM A 64M bit SDRAM x 32 bits is used as the RAM Fig 3 8 HL 1850 ...
Страница 86: ...HL 1850 1870N SERVICE MANUAL 3 9 Two 64M bit SDRAMs x 16 bits are used as the RAM Fig 3 9 HL 1870N ...
Страница 91: ...CHAPTER 3 THEORY OF OPERATION 3 14 Fig 3 15 ...
Страница 101: ...CHAPTER 3 THEORY OF OPERATION 3 24 ...
Страница 109: ...CHAPTER 4 DISASSEMBLY AND RE ASSEMBLY 4 2 ...
Страница 131: ...CHAPTER 4 DISASSEMBLY AND RE ASSEMBLY 4 24 Fig 4 39 ...
Страница 141: ...CHAPTER 4 DISASSEMBLY AND RE ASSEMBLY 4 34 Never touch the surface of the heat roller ...
Страница 148: ...CHAPTER 4 DISASSEMBLY AND RE ASSEMBLY 4 41 ...
Страница 158: ...CHAPTER 4 DISASSEMBLY AND RE ASSEMBLY 4 51 Fig 4 80 ...
Страница 160: ...CHAPTER 4 DISASSEMBLY AND RE ASSEMBLY 4 53 Fig 4 82 ...
Страница 167: ...CHAPTER 4 DISASSEMBLY AND RE ASSEMBLY 4 60 Fig 4 91 ...
Страница 169: ...CHAPTER 4 DISASSEMBLY AND RE ASSEMBLY 4 62 Fig 4 93 ...
Страница 172: ...CHAPTER 4 DISASSEMBLY AND RE ASSEMBLY 4 65 Fig 4 97 ...
Страница 174: ...CHAPTER 4 DISASSEMBLY AND RE ASSEMBLY 4 67 3 27 Harness Winding Form ...
Страница 183: ...CHAPTER 5 PERIODIC MAINTENANCE 5 8 ...
Страница 186: ...HL 1850 1870N SERVICE MANUAL 5 11 ...
Страница 194: ...CHAPTER 6 TROUBLESHOOTING 6 8 error in this chapter ...
Страница 202: ...CHAPTER 6 TROUBLESHOOTING 6 16 ...
Страница 205: ...HL 1850 1870N SERVICE MANUAL 6 19 ...
Страница 210: ...CHAPTER 6 TROUBLESHOOTING 6 24 ...
Страница 237: ...HL 1850 1870N SERVICE MANUAL 6 51 No Refer and compare with I 15 ...
Страница 255: ...HL 1850 1870N SERVICE MANUAL 6 69 ...
Страница 261: ...CHAPTER 7 HIDDEN FUNCTIONS 7 6 DRAM CHECK START START DRAM TEST Tests DRAM data ...
Страница 270: ...HL 1850 1870N SERVICE MANUAL 7 15 ...
Страница 271: ......
Страница 272: ...Appendix 1 Connection Diagram HL 1850 1870N A 1 ...
Страница 273: ...Appendix 2 Main PCB Circuit Diagram HL 1850 1870N 1 6 CODE LJ8453001 B512078CIR 1 6 A 2 NAME ...
Страница 274: ...Appendix 3 Main PCB Circuit Diagram HL 1850 1870N 2 6 CODE LJ8453001 B512078CIR 2 6 A 3 NAME ...
Страница 275: ...Appendix 4 Main PCB Circuit Diagram HL 1850 1870N 3 6 CODE LJ8453001 B512078CIR 3 6 A 4 NAME ...
Страница 276: ...Appendix 5 Main PCB Circuit Diagram HL 1850 1870N 4 6 CODE LJ8453001 B512078CIR 4 6 A 5 NAME ...
Страница 277: ...Appendix 6 Main PCB Circuit Diagram HL 1850 1870N 5 6 CODE LJ8453001 B512078CIR 5 6 A 6 NAME ...
Страница 278: ...Appendix 7 Main PCB Circuit Diagram HL 1850 1870N 6 6 CODE LJ8453001 B512078CIR 6 6 A 7 NAME ...
Страница 281: ...Appendix 10 Network Board PCB Circuit Diagram HL 1850 1870N CODE LJ8439001 A 10 NAME B512058CIR ...
Страница 282: ...Appendix 11 Low voltage Power Supply PCB Circuit Diagram 100V A 11 NAME Low voltage PS Circuit 100V ...
Страница 283: ...Appendix 12 Low voltage Power Supply PCB Circuit Diagram 200V A 12 NAME Low voltage PS Circuit 200V ...
Страница 284: ...Appendix 13 High voltage Power Supply PCB Circuit Diagram A 13 NAME High voltage PS Circuit ...
Страница 303: ...APPENDIX A 32 ...