C
H
APTER
3
TH
E
O
R
Y O
F O
PER
ATIO
N
3-
18
2. MECHANICS
2.
1
O
ve
rv
ie
w o
f P
rin
tin
g
Me
ch
an
is
m
Fig. 3-18
Fir
st e
je
ct r
olle
r
FI
X
ING
UNI
T
P
aper
PA
PER
C
A
SSETTE
Cl
eaner
P
hot
os
ens
iti
ve
drum
Tr
ans
fe
r rol
le
r
Dev
el
opm
ent
rol
le
r
Rear
regi
st
rat
ion
sens
or
lev
er
Front
regi
st
rat
ion
sens
or
lev
er
S
eparat
ion
pad
C
asse
tte
p
re
ssu
re
ro
lle
r
P
aper
pi
ck-up
rol
le
r
Fi
rs
t f
eed
rol
le
r
Toner
sens
or
DRUM
UNI
T
S
uppl
y
rol
le
r
B
lade
S
canner
m
ot
or
LA
SER
U
N
IT
Corona
wi
re
H
ea
t r
olle
r
S
ec
ond
ej
ec
t r
ol
le
r
P
aper
gui
de
Pr
essu
re
ro
lle
r
Rear
cov
er
Dupl
ex
out
er
gui
de
DUP
LE
X
T
RAY
Pr
essu
re
p
la
te
MP p
ic
k-
up
ro
lle
r
Fi
rs
t f
eed
pi
nc
h
rol
le
r
P
aper
fe
ed
rol
le
r
P
aper
fe
ed
pi
nc
h
rol
le
r
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 ...