CHAPTER 6 TROUBLESHOOTING
6-36
6.2
Troubleshooting Image Defect
Several types of the image defects can be cleared by end users. For those defects, instruct
the user to check the User Check items described in each table. Even if the same image
defect appears, the following procedures should be followed in the event of specific image
defects.
See also
subsection 6.3 Location of Ground Contacts
in this Chapter
for information about the
location of the grounding contacts.
!
CAUTION:
When using the printer for a special job, such as printing of name cards, print quality cannot be
guaranteed.
I-1
Light
Possible cause
Step
Check
Result
Remedy
Ground
contacts
Toner sensing
failure
(printer side)
1
Can printing be started with the
drum unit and toner cartridge
removed?
Yes
Check if the toner
sensor is dirty and
check the toner
sensor connection.
Toner sensing
failure
(toner cartridge
side)
2
Is the problem solved when 4
or 5 pages are printed after the
toner cartridge is replaced with
a full one?
Yes
The wiper of the toner
cartridge is defective.
Replace the toner
cartridge.
Drum
connection
failure
3
Are all the contacts between
the drum unit and printer body
connected correctly?
No
Clean contact
electrodes both on the
drum unit and in the
printer body.
(1), (4),
(5), (6)
High-voltage
power supply
PCB failure
4
Is the harness connection
between the high-voltage
power supply PCB and the
engine PCB correct?
Yes
Replace the high-
voltage power supply
PCB.
Engine PCB /
Main PCB failure
5
Is the harness connection
between the engine PCB and
the main PCB correct?
Yes
Replace the engine
PCB or the main PCB.
Dirt on the
scanner window
6
Is there any dirt on the scanner
window?
Yes
Wipe it off with a soft
clean paper.
Laser unit failure
7
Is the problem solved after
replacing the laser unit?
Yes
Replace the laser unit.
User Check
(1) Check the printers environment. Conditions such as humidity, high
temperatures, etc. may cause this situation to occur.
(2) If the whole page is light, toner save mode may be on. Disable toner save mode
within Printer Properties tab of the driver.
(3) Try installing a new toner cartridge or drum unit.
Summary of Contents for HL-1870N
Page 15: ...HL 1850 1870N SERVICE MANUAL xiii ...
Page 77: ...CHAPTER 2 INSTALLATION AND BASIC OPERATION 2 48 ...
Page 82: ...HL 1850 1870N SERVICE MANUAL 3 5 Fig 3 5 ...
Page 91: ...CHAPTER 3 THEORY OF OPERATION 3 14 Fig 3 15 ...
Page 101: ...CHAPTER 3 THEORY OF OPERATION 3 24 ...
Page 109: ...CHAPTER 4 DISASSEMBLY AND RE ASSEMBLY 4 2 ...
Page 131: ...CHAPTER 4 DISASSEMBLY AND RE ASSEMBLY 4 24 Fig 4 39 ...
Page 141: ...CHAPTER 4 DISASSEMBLY AND RE ASSEMBLY 4 34 Never touch the surface of the heat roller ...
Page 148: ...CHAPTER 4 DISASSEMBLY AND RE ASSEMBLY 4 41 ...
Page 158: ...CHAPTER 4 DISASSEMBLY AND RE ASSEMBLY 4 51 Fig 4 80 ...
Page 160: ...CHAPTER 4 DISASSEMBLY AND RE ASSEMBLY 4 53 Fig 4 82 ...
Page 167: ...CHAPTER 4 DISASSEMBLY AND RE ASSEMBLY 4 60 Fig 4 91 ...
Page 169: ...CHAPTER 4 DISASSEMBLY AND RE ASSEMBLY 4 62 Fig 4 93 ...
Page 172: ...CHAPTER 4 DISASSEMBLY AND RE ASSEMBLY 4 65 Fig 4 97 ...
Page 174: ...CHAPTER 4 DISASSEMBLY AND RE ASSEMBLY 4 67 3 27 Harness Winding Form ...
Page 183: ...CHAPTER 5 PERIODIC MAINTENANCE 5 8 ...
Page 186: ...HL 1850 1870N SERVICE MANUAL 5 11 ...
Page 194: ...CHAPTER 6 TROUBLESHOOTING 6 8 error in this chapter ...
Page 202: ...CHAPTER 6 TROUBLESHOOTING 6 16 ...
Page 205: ...HL 1850 1870N SERVICE MANUAL 6 19 ...
Page 210: ...CHAPTER 6 TROUBLESHOOTING 6 24 ...
Page 237: ...HL 1850 1870N SERVICE MANUAL 6 51 No Refer and compare with I 15 ...
Page 255: ...HL 1850 1870N SERVICE MANUAL 6 69 ...
Page 261: ...CHAPTER 7 HIDDEN FUNCTIONS 7 6 DRAM CHECK START START DRAM TEST Tests DRAM data ...
Page 270: ...HL 1850 1870N SERVICE MANUAL 7 15 ...
Page 271: ......
Page 272: ...Appendix 1 Connection Diagram HL 1850 1870N A 1 ...
Page 273: ...Appendix 2 Main PCB Circuit Diagram HL 1850 1870N 1 6 CODE LJ8453001 B512078CIR 1 6 A 2 NAME ...
Page 274: ...Appendix 3 Main PCB Circuit Diagram HL 1850 1870N 2 6 CODE LJ8453001 B512078CIR 2 6 A 3 NAME ...
Page 275: ...Appendix 4 Main PCB Circuit Diagram HL 1850 1870N 3 6 CODE LJ8453001 B512078CIR 3 6 A 4 NAME ...
Page 276: ...Appendix 5 Main PCB Circuit Diagram HL 1850 1870N 4 6 CODE LJ8453001 B512078CIR 4 6 A 5 NAME ...
Page 277: ...Appendix 6 Main PCB Circuit Diagram HL 1850 1870N 5 6 CODE LJ8453001 B512078CIR 5 6 A 6 NAME ...
Page 278: ...Appendix 7 Main PCB Circuit Diagram HL 1850 1870N 6 6 CODE LJ8453001 B512078CIR 6 6 A 7 NAME ...
Page 284: ...Appendix 13 High voltage Power Supply PCB Circuit Diagram A 13 NAME High voltage PS Circuit ...
Page 303: ...APPENDIX A 32 ...