Service Manuals, User Guides, Schematic Diagrams or docs for : . Various CHINA TV LCD LC-26HA27
<< Back | HomeMost service manuals and schematics are PDF files, so You will need Adobre Acrobat Reader to view : Acrobat Download Some of the files are DjVu format. Readers and resources available here : DjVu Resources
For the compressed files, most common are zip and rar. Please, extract files with Your favorite compression software ( WinZip, WinRAR ... ) before viewing. If a document has multiple parts, You should download all, before extracting.
Good luck. Repair on Your own risk. Make sure You know what You are doing.
Image preview - the first page of the document
>> Download LC-26HA27 documenatation <<
Text preview - extract from the document
LCD TELEVISION
LC-26HA37
CONTENTS
Safety precautions...................................................................................... 1
Alignment instructions ................................................................................ 3
Method of software upgrading...............................................................................
8
Working principle analysis of the unit...............................................................10
Block diagram.............................................................................................11
IC block diagram.........................................................................................12
Wiring diagram ........................................................................................ 19
Identification criteria for the bright spot and dark spot of the LCD screen.............. 20
Troubleshooting guide ................................................................................ 21
Schematic diagram.................................................................................... 26
APPENDIX-A: Assembly list
APPENDIX-B: Exploded View
Attention: This service manual is only for service personnel to take reference with. Before
servicing please read the following points carefully.
Safety precautions
1. Instructions
Be sure to switch off the power supply before replacing or welding any components or
inserting/plugging in connection wire Anti static measures to be taken (throughout the entire
production process!):
a) Do not touch here and there by hand at will;
b) Be sure to use anti static electric iron;
c) It's a must for the welder to wear anti static gloves.
Please refer to the detailed list before replacing components that have special safety requirements.
Do not change the specs and type at will.
2. Points for attention in servicing of LCD
2.1 Screens are different from one model to another and therefore not interchangeable. Be sure to
use the screen of the original model for replacement.
2.2 The operation voltage of LCD screen is 700-825V. Be sure to take proper measures in
protecting yourself and the machine when testing the system in the course of normal operation or
right after the power is switched off. Please do not touch the circuit or the metal part of the module
that is in operation mode. Relevant operation is possible only one minute after the power is
switched off.
2.3 Do not use any adapter that is not identical with the TV set. Otherwise it will cause fire or
damage to the set.
2.4 Never operate the set or do any installation work in bad environment such as wet bathroom,
laundry, kitchen, or nearby fire source, heating equipment and devices or exposure to sunlight etc.
Otherwise bad effect will result.
2.5 If any foreign substance such as water, liquid, metal slices or other matters happens to fall into
the module, be sure to cut the power off immediately and do not move anything on the module lest it
should cause fire or electric shock due to contact with the high voltage or short circuit.
2.6 Should there be smoke, abnormal smell or sound from the module, please shut the power off at
once. Likewise, if the screen is not working after the power is on or in the course of operation, the
power must be cut off immediately and no more operation is allowed under the same condition.
2.7 Do not pull out or plug in the connection wire when the module is in operation or just after the
power is off because in this case relatively high voltage still remains in the capacitor of the driving
circuit. Please wait at least one minute before the pulling out or plugging in the connection wire.
2.8 When operating or installing LCD please don't subject the LCD components to bending, twisting
or extrusion, collision lest mishap should result.
2.9 As most of the circuitry in LCD TV set is composed of CMOS integrated circuits, it's necessary
to pay attention to anti statics. Before servicing LCD TV make sure to take anti static measure and
ensure full grounding for all the parts that have to be grounded.
2.10 There are lots of connection wires between parts behind the LCD screen. When servicing or
moving the set please take care not to touch or scratch them. Once they are damaged the screen
1
would be unable to work and no way to get it repaired.
If the connection wires, connectors or components fixed by the thernotropic glue need to disengage
when service, please soak the thermotropic glue into the alcohol and then pull them out in case of
damage.
2.11 Special care must be taken in transporting or handling it. Exquisite shock vibration may lead to
breakage of screen glass or damage to driving circuit. Therefore it must be packed in a strong case
before the transportation or handling.
2.12 For the storage make sure to put it in a place where the environment can be controlled so as to
prevent the temperature and humidity from exceeding the limits as specified in the manual. For
prolonged storage, it is necessary to house it in an anti-moisture bag and put them altogether in one
place. The ambient conditions are tabulated as follows:
Temperature Scope for operation 0 ~ +50 oC
Scope for storage -20 ~ +60 oC
Humidity Scope for operation 20% ~ 85%
Scope for storage 10% ~ 90%
2.13 Display of a fixed picture for a long time may result in appearance of picture residue on the
screen, as commonly called "ghost shadow". The extent of the residual picture varies with the
maker of LCD screen. This phenomenon doesn't represent failure. This "ghost shadow" may remain
in the picture for a period of time (several minutes). But when operating it please avoid displaying
still picture in high brightness for a long time.
3. Points for attention during installation
3.1 The front panel of LCD screen is of glass. When installing it please make sure to put it in place.
3.2 For service or installation it's necessary to use specified screw lest it should damage the screen.
3.3 Be sure to take anti dust measures. Any foreign substance that happens to fall down between
the screen and the glass will affect the receiving and viewing effect
3.4 When dismantling or mounting the protective partition plate that is used for anti vibration and
insulation please take care to keep it in intactness so as to avoid hidden trouble.
3.5 Be sure to protect the cabinet from damage or scratch during service, dismantling or mounting.
2
Alignment instructions
1. Test equipment
PM5515 (video signal generator)
MK8258 (YUV, VGA signal generator)
CA210 (white balancer)
2. The alignment flow chart (see below figure)
Check DDC and FLASH
To produce signal board on the line
All testing
Auto correction
Connect with central signal source, then check each function of TV such as
station missing, analog control etc., check the output of headphone and speaker
Input AV/SVIDEO signal, then check each function of all the terminals
Input HD signal (format), then check each function of the terminal
Input VGA, HDMI signal, check if the display is normal, check each
function such as analog control etc., check horizontal /vertical center etc.
Preset ex-factory
Check the accessories and pack them in box
Fig-1 adjustment flow-chart
3. Description of adjustment
3.1 Unit adjustment
Connect the signal processing board, side AV board, button board and remote control receiver
board according to the wiring diagram. Connect with power and observe the display.
Method for using factory menu: press "INPUT" button, then press"2580" to enter level one factory
menu. Press "CH+" and "CH-" to select adjustment page, then press "OK" to access. Press "CH+"
and "CH-" to move cursor up and down, when the cursor stays on a certain adjustment item, press
3
"VOL-" and "VOL+" to adjust. Press "MENU" exit to the level one factory menu; press "EXIT" to exit
from the factory menu at any situation.
Note: channel switch isn't available at adjustment menu, only after return to level one factory menu,
you can switch channel.
3.2 Auto color adjustment
3.2.1 input 16 level gray-scale signal from MK8258 to D-sub channel, enter auto color adjustment
page of factory menu (AUTO COLOR), enter TEST PATTERN and use OK button to select GREY
SCALER16, then enter START and press OK.
3.2.2 input SMPTE COLOR BAR signal from MK8258 to YPbPr channel, enter auto color
adjustment page of factory menu (AUTO COLOR), enter TEST PATTERN and use OK button to
select SMPTE COLOR BAR, then enter START and press OK. (SMPTE COLOR BAR signal of
MK8258 should be OIRE standard, that's ATTER 96. TYPE CODE of PATTEREDID 6.)
Note: after auto color adjustment, it must press the power button on the remote controller to turn off
the unit and then turn on, can the information be stored in FLASH!
4 Performance check
4.1 TV function
Connect RF-TV terminal to the central signal source, enter the setup menu auto search, check if
there is station skipping, the output of earphone and speaker, the picture are normal. The signal
should include NTSC and ATSC.
4.2 AV/S-VIDEO terminal
Input AV/S signal, check if the picture and sound are normal.
4.3 YPbPr/YCbCr terminal
Input YUV signal (VG-849 signal generator), separate input YUV format signal of table 1 and check
if the picture and sound are normal.
Table 1 YUV signal format
No H-frequency (KHz) V-frequency (KHz) Signal
1 15.734 59.94 SDTV 480i
2 31.469 59.94 HDTV 480p
3 44.955 59.94 HDTV 720p
4 33.716 59.94 HDTV 1080i
4.4 VGA terminal
Input VGA signal (VG-849 signal generator), separate input VGA format signal of table 2 and check
if the picture and sound are normal. If the image is deflection of the H-field, select manual correction
of Advanced Video Menu.
4.5 HDMI terminal
HDMI signal format receives the three high-definition signals: 480I, 480P, 720P/60Hz, 1080I/60Hz,
except for the table 2 signal. Check if the image (contain HDCP ON and OFF) and sound are
normal.
Table 2 VGA signal format
Point clock pulse
No Resolution H-frequency(kHz) V-frenquency(Hz) Remark
frenquency(MHz)
1 720 X 400 31.469 70.086 28.322 IBM
2 640 X 480 31.469 59.94 25.175 IBM
4
3 640 X 480 37.861 72.809 31.5 VESA
4 640 X 480 37.5 75 31.5 VESA
5 640 X 480 43.269 85.008 36 VESA
6 800 X 600 35.156 56.25 36 VESA
7 800 X 600 37.879 60.317 40 VESA
8 800 X 600 48.077 72.188 50 VESA
9 800 X 600 46.875 75 49.5 VESA
10 800 X 600 53.674 85.061 56.25 VESA
11 1024 X 768 48.363 60.004 65 VESA
12 1024 X 768 56.476 70.069 75 VESA
13 1024 X 768 60.023 75.029 78.75 VESA
4.6 YPBPR and TV brightness check (use 100IRE white window signal)
5 Ex-factory setting of user menu
1) Select TV channel, volume: 25
2) Video menu, Picture Mode: Nature, Aspect Ratio: Wide
3) Video menu, Advanced Video Menu:
Noise Reduction----Spatial: On
Noise Reduction----Speckle: Off
Noise Reduction----Temporal: On
Sharpness: 0
Tine: 50
Color Temperature: Cool
3D Y/C: On
4) Audio menu, Sound Mode: News, Balance: 31, Earphone Vo1:31
Digital Audio Output: AC-3, MTS: Mono
5) Setup menu, Tuning Band: Air
6) Feature menu, Sleep Timer: Off, Menu Language: English
Note: Except for Color Temperature of Cool, the Advanced Video Menu of YPBPR/YCBCR and
VGA channels sets according to the adjustment of factory.
Trouble shooting
Before servicing please check to find the possible causes of the troubles according to the table
below.
1.Antenna(signal):
Picture is out of focus or jumping Bad status in signal receiving
Poor signal
Check if there are failures with the electrical connector or
the antenna.
Check if the antenna is properly connected.
Fringe in picture Check if the antenna is correctly oriented.
Maybe there is electric wave reflected from hilltop or
building.
Picture is interfered by stripe Possibly due to interference from automobile, train, high
5
shaped bright spots voltage transmission line, neon lamp etc.
Maybe there is interference between antenna and power
supply line. Please try to separate them in a longer
distance.
Maybe the shielded-layer of signal wire is not connected
properly to the connector.
There appear streaks or light color Check if interfered by other equipment and if interfered
on the screen possibly by the equipment like transmitting antenna, non
professional radio station and cellular phone.
2.TV set:
Symptoms Possible cause
Unable to switch the power on Check to see if the power plug has been inserted
properly into the socket.
No picture and sound Check to see if the power supply of liquid crystal TV has
been switched on. ( as can be indicated by the red LED
at the front of the TV set)
See if it's receiving the signal that is transmitted from
other source than the station
Check if it's connected to the wrong terminal or if the
input mode is correct.
Check if the signal cable connection between video
frequency source and the liquid crystal TV set is correct.
Deterioration of color phase or Check if all the picture setups have been corrected.
color tone
Screen position or size is not Check is the screen position and size is correctly set up.
proper
Picture is twisted and deformed Check to see if the picture-frame ratio is properly set up.
Picture color changed or colorless Check the "Component" or "RGB" settings of the liquid
crystal TV set and make proper adjustment according to
the signal types.
Picture too bright and there is Check if the contrast setting is too high.
distortion in the brightest area Possibly the output quality of DVD broadcaster is set too
high.
It maybe also due to improper terminal connection of the
video frequency signal in a certain position of the
system.
Picture is whitish or too bright in Check if the setting for the brightness is too high
the darkest area of the picture Possibly the brightness grade of DVD player
(broadcaster) is set too high.
No picture or signal produced from Check if the cable is disconnected.
the displayer if "XXX in search" Check if it's connected to the proper terminal or if the
appears. input mode is correct.
There appears an indication - Check if the TV set can receive input signal. The signal is
6
Symptoms Possible cause
"outside the receivable scope) not correctly identified and VGA format is beyond the
specified scope.
Remote control cannot work Check if the batteries are installed in the reverse order.
properly Check if the battery is effective.
Check the distance or angle from the monitor.
Check if there is any obstruct between the remote control
and the TV set.
Check if the remote control signal- receiving window is
exposed to strong fluorescence.
No picture and sound, but only Check if the antenna cable is correctly connected, or if it
hash. has received the video signal correctly.
Blur picture Check if the antenna cable is correctly connected.
Of if it has received the right video signal.
No sound Check if the "mute" audio frequency setting is selected.
Check if the sound volume is set to minimum.
Make sure the earphone is not connected.
Check if the cable connection is loose.
When playing VHS picture search When being played or in pause VHS picture search tape
tape, there are lines at the top or sometimes can't provide stable picture, which may lead
bottom of the picture. to incorrect display of the liquid crystal TV, In this case
please press "auto" key on the remote control so as to
enable the liquid crystal TV set to recheck the signal and
then to display correct picture signal
7
Method of software upgrading
1. Connect computer serial port and TV parallel port with serial wire 665.D0002-645.
2. Open iDev.exe
3. Click , enter the setting interface.
Set Serial Port to the current COM port, set the Baud Rate to 1152000, Image Path to the path of the
new software. If the new software renews Bootcode, pitch on "Update boot sector" option and then click
OK.
4. Click to enter the interface below:
8
5. Turn on the TV, the software begins to be written.
6. After the software written, Press the power key (local keypad) and holding for several second to
force power off TV set,
7. Turn on the TV again and enter the factory menu initialization setting.
9
Working principle analysis of the unit
1. NTSC signal flow:
Antenna reception NTSC signal send to the integrative tuner TDQDU4-508A, which contains HF
and IF amplifier circuit and video decoding circuit. It is controlled by main IC ZR39760 (integrate
CPU) through I2C bus. The NTSC signal via frequency tuning, HF amplification, IF amplification,
system switching and decoding, output video signal TV-CVBS of 1Vpp and sound IF signal (SIF).
TV-CVBS, AV1-CVBS, AV2-CVBS input from AV terminal and S-VIDEO via switch IC N52797EP to
output signal, one way send to ZR39760 for VEDIO DECODER, DEINTERLACE and SCALER,
then send to LVDS level drive for LCD screen, another way is output through AV output socket as
AV OUT.
The sound IF (SIF) is fed into demodulation IC ZR39760, via decoding and A/D conversion, it is fed
into ZR39760 for analog control in the format of I2S. ZR39760 outputs audio data of I2S format, it is
fed into audio D/A converter IC CS4344, output analog L/R signal. The L/R signal and sound signal
of PC/YPRPB via diverter switch HEF4052BT, send to R2S15903SP (sound processing and volume
control). Select right/left sound channel, their send to class D sound amplifier R2S15102 amplify,
then send to speaker.
2. ATSC signal flow:
Antenna reception ATSC signal send to tuner TDQU4-508A, after frequency tuning, HF
amplification, IF amplification and SAW FILTER, fed to ZR39760 for information source decoding in
the format of standard serial TS stream.
HD video signal via decoding to A/D conversion and OSD superposition, at last send to LVDS drive
level for LCD panel.
HD audio signal, via decoder built-in ZR39760, resumed to multi- channel sound of Dolby AC-3, at
the same time output data stream of I2S format and S/PDIF data stream. Audio data of I2S format is
fed to audio D/A converter chip CS4344 to output analog L/R signal. S/PDIF data stream directly
output from optical fiber interface.
3. PC/YPrPb signal flow
PC and two YPBPR signal via matched resistance, it a-c couple to video switch SN74CBT3257CDR,
via switching to selected signal to Triple Video A/D Converter MST9883 A/D conversion. Send
B/G/B of 24 bit to main IC ZR39760 digital decode, image scale and OSD superposition, then send
to LVDS level drive for LCD screen.
Sound signal (PC, YPrPb) via switch diverter HEF4052BT to output signal, it send to R2S15903SP
(sound processing and volume control) switch of audio. Select right/left sound channel, their send to
class D sound amplifier R2S15102 amplify, then send to speaker.
4. HDMI signal flow
HDMI video signal is directly fed to main IC ZR39760 (with HDCP function of HDMI) digital decode,
image scale and OSD superposition, then output LVDS drive level for screen.
HDMI audio signal, via decoder built-in ZR39760, output data stream of I2S format and S/PDIF data
stream at the same time. Audio data of I2S format is fed to audio D/A converter chip CS4344 to
output analog L/R signal. S/PDIF data stream directly output from optical fiber interface.
10
YPbPr Audio1 YPbPr Audio2 AV1 AV2 PC AUDIO
Block diagram
earphone socket
with
R2S15102
M52797SP switch
CD4052
AV Audio Out
R2S15903
CS5340
AV Out
I2S
NTSC CVBS CS4345
11
ATSC/NTSC TNUER
ATSC DIF
I2S
Y KEY
S Video PLC915
C I2C IR
YPBPR1 P15V
330 I2C
P15V CAT99
YPBPR2 PW2300
330
83
PC ZR39760 LVDS
PANEL
RS232 MAX3232C
SPI 32M Flash
HDMI1 FSHDMI04+PI5V330
HDMI2
DDR 256M
SDRAM
IC block diagram
1. ZR39760
12
2. MST9883
MST9883 is a Triple Video A/D Converter with Clamps & Pixel Clock Synthesizer. The triple ADC
support 12 - 110 MHz Sampling Rate. It integrated 5-bit pixel clock phase adjustment for precise
sample timing control. Its Output support 4:2:2 Format Mode and it can Pin Compatible with
AD9883A.
Block diagram of MST9883 is flow:
13
14
Pin configuration of MST9883:
Pin descriptions of MST9883:
54: Red analog input
48: Green analog input
43: Blue analog input
49: Sync on Green analog input
38: External Clamp Input
30: Horizontal SYNC Input
31: Vertical SYNC Input
29: Hold PLL Frequency, do not track HSYNC
56: Serial Interface clock
57: Serial Interface data pin
55: Serial interface address pin
70-77: Red output data
2-9: Green output data
12-19: Blue output data
67: Output data clock
66: HSYNC output
64: VSYNC output
39,42,45,46,51,52,59,62: Analog Power
15
26,27,34,35: PLL Power
11, 22, 23, 69,78,79: Digital Output Power
1,10,20,21,24,25,28,32,36,40,41,44,47,50,53,60,61,63,68,80:Ground
3. R2S15903SP
R2S15903SP is an audio signal processor. It has MUTE and Volume/Tone control. It can support 5
input selector.
Pin descriptions of R2S15903SP:
5, 28: AV OUT INPUT L/R
2, 31: other channels
17, 18:I2C SDA/SCL
32: Power Supply
16
4. RS15102
RS15102 is the high effective D type of power amplifier. The output power can reach 20W (10%
THD+N) with 8- speakers, +18V power supply, eliminating the need for heat sinks.
Pin description:
1: audio-out, left audio output
15: audio-out, right audio output
11: audio-in, left audio input
5: audio-in, right audio input
14: mute1
17
5. M52797SP AV switch with I2C bus control
Pin description:
1 VCC 9V 17 VIDEO OUT
2, 4 AV2 L R IN 19, 21 L R OUT
2 AV2 VIDEO IN 20 AV CVBS OUT
6 TV-CVBS IN 23 TUNER_IN
5, 7 Y Pr Pb1 L R IN 22, 24 TV L R IN
8, 10 Y Pr Pb2 L R IN 11, 12 SCL, SDA
18
Wiring diagram
19
Identification criteria for the bright spot and dark spot of the LCD screen
Quantity allowed Distance between two spots
Category Criteria
15" 20" 22" 30" 40" 15" 20" 22" 30" 40"
One single
5 2 5 2 3
spot
Bright Two
15mm
spot neighboring 2 1 2 1 1
spots
Total No. 5 2 5 2 3
15mm
One single
6 7 5 4 10
spot
Dark Two
10mm 5mm
spots neighboring 2 2 2 1 5
spots
Total No. 6 7 5 4 10
Total defected point 8 7 5 4 /
Notes:
1. Definition of defected point (bright spot, dark spot): It is identified as a defected point if its area
exceeds 1/2 of a single picture element (R, G, B).
2. Definition of bright spot: It is identified as a bright spot if it is bright in the state of dark field and its
bright size remains unchanged
3. Definition of dark spot: It is identified as a dark spot if it is dark in the state of white field and its
dark size remains unchanged
4. Definition of two neighboring points: Defects of a group of picture elements (RB, RG, GB).
20
Troubleshooting guide
Begin
Turn on the TV? No Check if XP1 9# on the main board is 3.3V,
if it's 0V, check the power supply of the
power board.
A green indicator Check if the pin3 of XP1 on the main board
No
lights? is high level(+5V)? if not, check the power
board and NP2.
Yes
Check if the power supply of main board is
normal? Then check the power supply of
Display picture? No
each IC, if the crystal starts, DDR clock is
correct?
Yes
Check the signal inputted from the channel to
If the picture of each channel
No pin IC or IC and its peripheral circuit or the
is normal?
output of LVDS is normal
Check if the signal inputted from the channel
If the sound of each channel is No to pin IC is normal or IC (R2S15903,
normal?
RS15102, CS5340, CS4345) and their
periphery are normal
(1) abnormal picture
a) Failure with RA125, RA124 on the main board, which may lead to panel abnormal
b) A certain differential wire pair of LVDS of X41(RX0+/-, RX1+/-, RX2+/-, RX3+/-) is abnormal,
which may lead to lack of color or color splash.,
c) Failure with NA25, which may lead to loss of corresponding color from the gray degree
corresponding to the picture of channel HDMI.
d) Failure with NA102,NB21 and their peripheral circuit, which may lead to picture abnormal of
PC, YPbPr and YCbCr.
e) Failure with N100 on the image processing board, which may lead to picture abnormal in all
channels.
21
(2) no picture, no sound
No picture, no sound
Check the color of indicator
light
If XP1 9# is 3.3V? Blue
Check the power Check the output voltage of
board sockets XP1, XV2
Yes
No
No sound No picture Power board problem
Refer to (3) checking Refer to (4) checking
procedure procedure
(3) with picture but no sound
With picture but no sound
Check if the voltage of sound amplifier
of XV2 in main board is normal?
No
Yes
Check if RV12, RV13 inputs Check the power board
signals
Yes No
Check NV1 and its Check NV3/NV2/NB12
peripheral circuit and their peripheral circuit
22
(4) with sound but no picture
With sound but no picture
Display OSD MENU?
Yes
Display LOGO?
Yes No
If there is no picture Check if the crystal in data processing board starts,
in all channels? DDR clock and DDR SDRAM are normal?
Yes No
Check N100 and Refer to (6), (7), (8), (9), (10),
its peripheral circuit (11), (12) checking procedure
Yes No
Check the power supply of N100 Check the power supply of N100 (on digital
on the image processing board processing board) and DDR and their periphery.
(5) S-Video or AV no picture
Check if CB106 and CB49 input signals? (AV IN)
Check if LB7, LB8 input signals? (S-Video)
Yes No
Check if pin20 of NB8 Check N105/N106 and the circuit
outputs signals? from AV terminal to N104
Yes No
Check N100, CB153 and Check NB8 and its
their periphery circuit periphery circuit
23
(6) NTSC channel no picture
Check if pin4 of TUN1 output
signals?
Yes No
Check if CB154 outputs Check TUN1 power supply and
signals? the peripheral circuit.
Yes
Check N100 and its
periphery circuit
(7) ATSC channel no picture
Check if pin20/21 of TUN1
output signals?
Yes No
Check if the crystal is Check TUN1 power supply and
normal? If output signal? the peripheral circuit.
Yes No
Check socket N100 and the Check the crystal and
periphery. periphery circuit.
Note :
The I2C bus line control of TUNER is switch through the bus line of N228, so after checking the power
supply and peripheral circuit of TUNER226, it is still no picture in NTSC and ATSC channel, please
check N228 emphatically.
24
(8) Troubleshooting guide of power supply board
a. No power supply
No power supply
Check if X501 FU501 is
Does AC voltage at C502 N
properly inserted?
Y
Does DC voltage at C514
(300~385V) N Check D501, R513, D502
Y
Check if the 15V DC of Check N503 or peripheral
N
N503 (pin12) circuit
Y
Supplementary power
supply N502 has problem
b. No DC voltage output
No DC voltage output
Check if DC voltage of C550 is
N Check N502 or peripheral
3.3V(5V)
circuit
Y
Check if DC voltage of V505 B N Main board has problem, or
is 24V It didn't send out high level
control signal
Y
Check if DC voltage of C541 is
N
12V Check N503, T501 or D516
Y
Problem exits in FU502, or there is
shortage on the main board
25
APPENDIX-A: Main assembly
Model Part name No.
LC-26HA37 Digital processing board 667.26HA18-69
Key board 667.26HA37-05
IR receiver board 667.26HA37-09
Power board 667.26HA37-20
Interface board 667.26HA37-29
Remote control 301.D26HA37-12A
Panel 335.26009-00
603-L26HA37-13
Ver.1.0
◦ Jabse Service Manual Search 2024 ◦ Jabse Pravopis ◦ onTap.bg ◦ Other service manual resources online : Fixya ◦ eServiceinfo