Sharp LC-15B2E (serv.man2) Service Manual ▷ View online
10
LC-13B2H/M
LC-15B2H/M
LC-20B2H/M
LC-15B2H/M
LC-20B2H/M
3-4. Component signal processing circuit
The component signal from the analog board is inputted to the input port (
4
,
5
,
6
) of IC801 (video decoder).
The video signal (pin (70)) outputted from IC801 is subjected to sync separation in Q401 (buffer) and IC401
(sync separator) and then inputted to the CSYNC port (
(sync separator) and then inputted to the CSYNC port (
6
) of IC2001.
The component signal inputted to IC801 is AD-converted in the IC and then inputted to IC1201 (LCD controller).
From CVIN and CSYNC inputted to IC2001, CK, VD, HD, OSD-RGB, MPCLK, MPDA and MPCS are outputted
to IC1201. At the same time, MPDA and MPCLK are inputted to the gray level circuit.
The component signal inputted to IC1201 is RGB-converted in the IC and then outputted to the LCD panel. At
the same time, GCK is inputted to IC1203, IC1204 and IC1205 (gate control) and then outputted to the LCD
panel.
From CVIN and CSYNC inputted to IC2001, CK, VD, HD, OSD-RGB, MPCLK, MPDA and MPCS are outputted
to IC1201. At the same time, MPDA and MPCLK are inputted to the gray level circuit.
The component signal inputted to IC1201 is RGB-converted in the IC and then outputted to the LCD panel. At
the same time, GCK is inputted to IC1203, IC1204 and IC1205 (gate control) and then outputted to the LCD
panel.
BUFFER
Q402
SYNC
SEPARATER.
IC401
BUFFER
Q401
COMPONENT
INPUT
YPbPr
VIDEO
DECODER
(VPC)
IC801
IC801
I
2
C
Y, PB, PR
VOUT
3.3V REG.
CSYNC0
CVIN
MPU
IC2001
Data, clock, etc. are inputted.
AD-converted
data is inputted.
data is inputted.
1-5. LCD
CONTROLLER
CIRCUIT
LCD
PANEL
RGB-converted
data is outputted.
data is outputted.
OSD data etc. is inputted.
1-3. GRAY
LEVEL
CIRCUIT
Gray level reference
voltages and electrode
signals are outputted.
voltages and electrode
signals are outputted.
Fig. 3-5. Component signal processing circuit
3-5. LCD controller circuit
The Y/UV signal from IC801 and the VD, HD, BK, CK and OSD-RGB signals for OSD inputted to pins (95), (97),
(21), (17) and (32) thru (34) from IC2001 are subjected to RGB conversion, PAL pixel skipping 7-6 line conver-
sion and 8-6 bit conversion in IC1201 and then outputted as RGB 6-bit data to the LCD panel (R0-5: pins (89)
thru (86), G0-5: pins (98) thru (93), B0-5: pins (108) thru (103)).
The LCD controller also outputs the timing signal at the time of vertical and horizontal reverse display control
and light control.
(21), (17) and (32) thru (34) from IC2001 are subjected to RGB conversion, PAL pixel skipping 7-6 line conver-
sion and 8-6 bit conversion in IC1201 and then outputted as RGB 6-bit data to the LCD panel (R0-5: pins (89)
thru (86), G0-5: pins (98) thru (93), B0-5: pins (108) thru (103)).
The LCD controller also outputs the timing signal at the time of vertical and horizontal reverse display control
and light control.
VIDEO
DECODER
IC801
FIFO
IC1202
LCD
CONTROLLER
IC1201
GATE
CONTROL
IC1203
IC1204
IC1205
IC1204
IC1205
MPU
IC2001
VSY, HSY, FIELD, VACT,
UV0-7 (
UV0-7 (
7
–
0
)
R0-5 (
q
–
r
), G0-5, B0-5
CK, SPIO, SPOI, LBR, HG
CK, VD, HD, OSD-RGB
GCK
GCK
MPCS, MPCLK, MPDA
VP_Y0-7 (
3
–
6
)
LCD
PANEL
Fig. 3-7. LCD controller circuit
~ 3
thru
r
are waveform measurement points.
11
LC-13B2H/M
LC-15B2H/M
LC-20B2H/M
LC-15B2H/M
LC-20B2H/M
VP Y0
VP Y1
VP Y2
VP Y3
Measurement points
3
–
6
UV0
UV1
UV2
UV3
Measurement points
7
–
0
OR0
OR1
OR2
OR3
Measurement points
q
–
r
Y signal output of IC801 (VP_Y0-3)
C signal output of IC801 (UV0-3)
R signal output of IC1201 (OR0-3)
3-6. Gray level circuit
DAC1CS, MPCLK and MPDA outputted from IC2001 are inputted to IC1101 (DAC) (
t
,
y
,
u
). After passing
through IC1102-08 and IC1110, the gray level reference voltages (V0, V16, V32, V46 and V63) are outputted to
the panel. After passing through IC1109 and Q1101-1102, the electrode signals (VCOM and VCSCOM) are
outputted to the panel.
the panel. After passing through IC1109 and Q1101-1102, the electrode signals (VCOM and VCSCOM) are
outputted to the panel.
MPU
IC2001
DAC
IC1101
LCD
PANEL
COMMON
IC1109
Q1101
Q1102
Q1102
GRADUATION
POWER FOR
LCD
IC1102-IC1108
IC1110
MPCLK, MPDA
V0, V16, V32, V48, V63
VCOM, VCSCOM
DAC1CS
Fig. 3-8. Gray level circuit
12
LC-13B2H/M
LC-15B2H/M
LC-20B2H/M
LC-15B2H/M
LC-20B2H/M
3-7. Power supply circuit
5V, 3.3V, 9V, 12V, 13V, 29V, 31V and -8V are outputted.
The DC power supply from the AC adapter is inputted to the inverter circuit, audio IC, power supply circuit,
microcomputer IC (IC2001) and power supply IC.
In the power supply circuit, the DC power supply from the AC adapter is inputted to the transformer (T3701).
The transformer outputs the voltages (31V, 29V, 5V and -8V) smoothed in the diode and electrolytic capacitor
connected to the output terminal from DC power supply input.
The DC power supply from the AC adapter is inputted to the inverter circuit, audio IC, power supply circuit,
microcomputer IC (IC2001) and power supply IC.
In the power supply circuit, the DC power supply from the AC adapter is inputted to the transformer (T3701).
The transformer outputs the voltages (31V, 29V, 5V and -8V) smoothed in the diode and electrolytic capacitor
connected to the output terminal from DC power supply input.
»
Output voltage circuits
(1) BTU5V and B5V circuit
The output from pin (7) of the transformer (T3701) is rectified and smoothed in D3707, C3720, C3721
and C3722 to supply BTU5V. BTU5V is smoothed in L3702, C3727 and C3728 to supply stable B5V.
and C3722 to supply BTU5V. BTU5V is smoothed in L3702, C3727 and C3728 to supply stable B5V.
(2) 5V (for microcomputer power supply) circuit
The DC power supply from the AC adapter is inputted to pin (1) of the regulator IC (IC701) after passing
through the buffer transistor and stable 5V is supplied from pin (3).
through the buffer transistor and stable 5V is supplied from pin (3).
(3) 3.3V circuit
B5V is supplied to pin (1) of the regulator IC (IC701) and stable 3.3V is supplied from pin (3).
(4) 9V circuit
The output from pin (8) of the transformer (T3701) is rectified and smoothed in D3706, C3718, C3717
and L3703 to supply 9V.
and L3703 to supply 9V.
(5) 12V circuit
The DC power supply from the AC adapter is rectified and smoothed in C3710, C3700 and Q3700 to
supply stable 12V.
supply stable 12V.
(6) 13V circuit
The DC power supply from the AC adapter is rectified and smoothed using the electrolytic capacitor etc.
and supplied to each circuit.
and supplied to each circuit.
(7) 29V and 31V circuit
The output from pin (10) of the transformer (T3701) is rectified and smoothed in D3704, C3714 and
C3715 and stable 29V and 31V are supplied using the operational amplifier IC (IC3702), Q3707, Q3704,
Q3705, Q3706 and D3709.
C3715 and stable 29V and 31V are supplied using the operational amplifier IC (IC3702), Q3707, Q3704,
Q3705, Q3706 and D3709.
(8) -8V circuit
The output from pin (6) of the transformer (T3701) is rectified and smoothed in D3708, C3724, C3725
and L3704 to supply stable -8V.
and L3704 to supply stable -8V.
Fig. 3-9. Power supply circuit
DC IN
DC13V
(12V for
13/15)
DC/DC
T3701
IC3701
Q3700
Q3701
Q3702
Q3701
Q3702
38V
16V
9V
5V
-8V
REGULATOR
IC3702
31V
Q3707
29V
Q3704
14V
Q3705
8V
Q3706
3.3V
IC701
Regulator (supplying 5V for microcomputer)
Inverter circuit
Audio amplifier IC
13
LC-13B2H/M
LC-15B2H/M
LC-20B2H/M
LC-15B2H/M
LC-20B2H/M
3-8. Inverter circuit
13V (12V for 13/15B2U) inputted from the AC adapter passes through the DC/AC converter circuit composed of
a transformer and a LC oscillation circuit to supply stable AC power to the lamp.
a transformer and a LC oscillation circuit to supply stable AC power to the lamp.
DC12V
(13/15B2H/M)
Buffer
Q5701
Q5702
Q5703
Q5702
Q5703
Transformer
T5701
T5702
T5702
High voltage
power supply
(lamp power supply)
DC13V
(20B2H/M)
Buffer
Q6751
Q6752
Q6755
Q6752
Q6755
Transformer
T6751
T6752
T6753
T6752
T6753
Transformer
T6551
T6552
T6553
T6552
T6553
Buffer
Q6551
Q6552
Q6555
Q6552
Q6555
High voltage
power supply
(lamp power supply)
High voltage
power supply
(lamp power supply)
Fig. 3-10. Inverter circuit (20B2H/M)
Fig. 3-11. Inverter circuit (13/15B2H/M)
3-9. Lamp error detection circuit
For safety, this LCD color television has a function to turn OFF the power automatically when an abnormal
condition occurs in the lamp or lamp circuit (lamp error detection). If an abnormal condition should occur in the
lamp or lamp circuit, D3600-03 and Q3600-02 will operate to send a lamp error signal to IC2001 (pin (42)),
resulting in the following:
condition occurs in the lamp or lamp circuit (lamp error detection). If an abnormal condition should occur in the
lamp or lamp circuit, D3600-03 and Q3600-02 will operate to send a lamp error signal to IC2001 (pin (42)),
resulting in the following:
1
About 5 seconds after the power of the television main body is turned ON, the power is turned OFF. (The
power LED located on the front of the television changes from green to red.)
power LED located on the front of the television changes from green to red.)
2
If
1
is repeated five times successively, it becomes impossible to turn ON the power. (The power LED
remains red.)
~
For measures to be taken, refer to the service manual.
Fig. 3-12. Lamp error circuit
LAMP
D3600
D3601
D3601
D3602
D3603
D3603
Q3600
Q3601
Q3602
Q3601
Q3602
L.ERR
IC2001
Click on the first or last page to see other LC-15B2E (serv.man2) service manuals if exist.