LiteOn B17AAU User manual

17-inch LCD Monitor
B17AAU/B17ANU/B17AAY
Service Manual

Service ManualVersionsand Revision
Copyright
Copyright2002LiteOnTechnologyCorp.
AllRightsReserved
Thismanualmaynot,inwholeorinpart,becopied,
photocopied,reproduced,translated,orconvertedto
anyelectronicormachinereadableformwithout
priorwrittenpermissionofLiteOnTechnology
Corp.
B17AAU/B17ANU/B17AAYServiceManual.
Printed in Taiwan.
Trademarks
LiteOnisaregisteredtrademarkofLiteOn
TechnologyCorp.
Allothertrademarksarethepropertyoftheir
respectiveowners.
No. Version Release Date Revision
1. 1.0 Feb. 5, 2002 Original release
2. 1.1 June 21, 2002 Spare parts location update
Item 4, 8, 17

Circuit Description Index
B1 AAU / B1 ANU / B1 AAY
1. Audio circuit --------------------------------------------------------------------------------------------------------------- 1
1.1 Audio input ------------------------------------------------------------------------------------------------------------ 1
1.2 Audio output ---------------------------------------------------------------------------------------------------------- 1
2. Power supply -------------------------------------------------------------------------------------------------------------- 1
3. Video input circuit -------------------------------------------------------------------------------------------------------- 1
4. De inition converter LSI peripheral circuit ---------------------------------------------------------------------------- 1
5. System reset, LED control circuit --------------------------------------------------------------------------------------- 1
6. E2PROM or PNP --------------------------------------------------------------------------------------------------------- 1
7. E2PROM -------------------------------------------------------------------------------------------------------------------- 2
8. CPU circuit ----------------------------------------------------------------------------------------------------------------- 2
8.1 Dection o POWER switch status ---------------------------------------------------------------------------------- 2
8.2 Display mode identi ication ----------------------------------------------------------------------------------------- 2
8.3 User control ----------------------------------------------------------------------------------------------------------- 4
8.4 Control o identi ication converter LSI (IC 14) ------------------------------------------------------------------ 5
8.5 I2C bus control -------------------------------------------------------------------------------------------------------- 5
8.6 Power ON sequence -------------------------------------------------------------------------------------------------- 6
8.7 Power OFF sequence ------------------------------------------------------------------------------------------------- 7
8.8 List o CPU assignments --------------------------------------------------------------------------------------------- 8
9 Power Board Operation Therory ------------------------------------------------------------------------------------------- 8
Table of Contents

Page 1Circuit Description
B1 AAU / B1 ANU / B1 AAY
1. Audio circuit (Circuit diagrams Main PWB) KT
1.1 Audio input
The audio signal input received rom the audio input terminal (P311) is applied to the ampli ier I332 o 4 (L-CH)
and 9 (R-CH) through the low-pass ilter consisting o R408, R410, R409, R407, C598 and C599.
In this ampli ier, controls o Volume, and mute are conducted. The audio signal controlled at the pin 6 deter-
mines the attenuation o output o the ampli iers. Since then, the signal is output to the jack P312.
1.2 Audio output
The audio signal is output rom the jack output terminal (P312) o the jack board to the internal speaker system.
2. Power supply (Circuit daigrams MAIN PWB 6/8, 7/8)
2.1 P310 connector
A 5V power supply or LCD module, CPU, and logic is generated rom the P310 connector.
2.2 I323:3-terminal regulator
A 3.3V power supply or Scaler IC I315, LVDS IC I319, I320 is generated rom the 5V source.
2.3 I324:3-terminal regulator
A 2.5V power supply or Scaler IC I315 is generated rom the 5V source.
Q307, I321 ON/OFF control or LCD Module
ON/OFF control is per ormed or power ON/OFF and also or the power saving sequence.
3. Video input circuit (Circuit diagram MAIN PWB 3/8)
The analog video signal input entered rom P304, the AC-coupled video signal is used to clamp the black level at
0V).
4. De inition converter LSI peripheral circuit (Circuit diagram MAIN PWB)
I315 gm5020 is the de inition converter LSI.
The analog R, G, B signal input entered rom the video input circuit is converted into the digital data o video
signal through the incorporated A/D converter. Based on this conversion, this device per orms interpolation
during pixel extension. The source voltage or this device is 3.3V, 2.5V and the system clock requency is
24MHz. The withstand voltage level or the input signal voltage i I315 is 3.3V and 5V.
5. System reset, LED control circuit (Circuit diagram MAIN PWB 2/8)
5.1 System reset
System reset is per ormed by detecting the rising and alling o the 5V source voltage at I301.
5.2 LED control circuit
Green / amber is lit with the control signal o the LED GREEN and LED AMBER signal pin 25, 26 rom I302
(Circuit diagram MAIN PWB 2/8).
6. E2PROM or PnP (Circuit diagram MAIN PWB 3/8)

Page 2 Circuit Description
B1 AAU / B1 ANU / B1 AAY
7. E2PROM (Circuit diagram MAIN PWB 2/8)
Data trans er between I305 (24LC16) and CPU (Circuit diagram MAIN PWB 2/8 (I302) is e ected through the
IIC bus SCL (pin 17) and SDA (pin 16) o I302. The data to be trans erred to each device are stored in I305.
l I315 control data.
l OSD related setting data.
l Other control data or service menu.
8. CPU circuit (Circuit diagram MAIN PWB 2/8)
I302 (87C51RD2) unctions as the CPU.
The source voltage or the device is 5.0V and the system clock requency is 24MHz.
8.1 Detection o POWER switch status
The CPU identi ies the ON status o the two power supplies. The identi ication is made when the power supply
is turned o . For example, i the power supply is turned o with the POWER switch, the POWER switch must be
turned on when activating the power supply again. I the power supply is turned o by pulling out the power
cord, then this power supply can be turned on by connecting the power cord, without pressing the POWER
switch.
8.2 Display mode identi ication
8.2.1 Functions
(1) Display mode identi ication
l The display mode o input signal is identi ied based on Table 1.
l When the mode has been identi ied through the measurement o horizontal and vertical requencies, the total
number o lines is determined with a ormula o  Horizontal requency / Vertical requency = Total number
o lines. Final identi ication can be made by examining the coincidence o the obtained igure with the
number o lines or the mode identi ied rom the requency. The boundary number o lines in each mode is
shown in Table 2.
l When the detected requency i the sync signal has changed, the total number o lines should be counted even
through it is rge identi ied requency in the same mode.
(2) Power save mode.
This power save mode is assumed when the requency o the horizontal / vertical signal is as speci ied below.
l Vertical requency : 50 ~ 86 Hz
l Horizontal requency : 24 ~ 92 KHz
lVTOTAL : 1200 or more.
(3) Power save mode.
The power save mode is assumed when the horizontal / vertical signals are as speci ied below.
l I there is no horizontal sync signal input.
l I there is no vertical sync signal input.
l I the horizontal sync signal is outside the measuring range o gm5020.
l I the vertical sync signal is outside the measuring range o gm5020.

Page 3Circuit Description
B1 AAU / B1 ANU / B1 AAY
Table 1
PolarityMode Resolution H- re
q
(
KHz
)
Band Width
(MHz) HV
1. VGA 720 x 400 70Hz 31.47 28.322 - +
2. VGA 640 x 480 60Hz 31.47 25.175 - -
3. MAC 640 x 480 66Hz 35 32.24 - -
4. VESA 640 X 480 72Hz 37.86 31.5 - -
5. VESA 640 X 480 75Hz 37.5 31.5 - -
6. VESA 800 x 600 56Hz 35.16 36 + +
7. VESA 800 x 600 60Hz 37.88 40 + +
8. VESA 800 x 600 75Hz 46.88 49.5 + +
9. VESA 800 x 600 72Hz 48.08 50 + +
10. MAC 832 x 624 75Hz 49.72 57.283 - -
11. VESA 1024 x 768 60Hz 48.36 65 - -
12. VESA 1024 x 768 70Hz 56.48 75 - -
13. VESA 1024 x 768 75Hz 60.02 78.75 + +
14. VESA 1280 x 1024 60Hz 64 108 + +
15. VESA 1280 x 1024 75Hz 80 135 + +
16. VESA 1152 x 864 75Hz 67.5 108 + +
17. VESA 1280 x 960 60Hz 60 108 + +

Page 4 Circuit Description
B1 AAU / B1 ANU / B1 AAY
Table 2 the number o the lines, Vsync distinction
8.3 User Control
8.3.1 Related ports o I315 and pin o I302
Indication resolution The number o the
distinction lines
Distinction Vsync The ixed mode
640 x 480 487 < LINE < 607 V < 63 Hz 2
63 Hz < V < 68 Hz 3
68 Hz < V < 74 Hz 4
74 Hz < V < 78 Hz 5
800 x 600 607 < LINE < 777 V < 58 Hz 6
58 Hz < V < 63 Hz 7
63 Hz < V < 73 Hz 9
73 Hz < V < 78 Hz 8
832 x 624 640 < LINE -10
1024 x 768 768 < LINE < 870 V < 63 Hz 11
68 Hz < V < 73 Hz 12
73 Hz < V < 78 Hz 13
1152 x 864 870 < LINE < 1031 16
1280 x 960 960 < LINE < 1027 17
1280 x 1024 1027 < LINE 14,15
8.3.2 Functions
Control is e ected or the push-switches to be used when the user changes the parameters, in order to modi y the
respective setting values. Whether the switch has been pressed is identi ied with the switch input level that is
turned L.
Each switch input port is pulled up at outside o ASIC
Each parameter is stored in the EEPROM, the contents o which are updated as required.
.
Port Pin No. I/O Si
g
nal name Function Remarks
GPI04 I315
,
M1 1 MENU EXIT/ENTER switch in
p
ut ENTER/Withdraw
rom OSD
GPI05 I315
,
L1 1 DOWN switch input ( ) key
GPI06 I315
,
G18 1 - switch input ( ) key
GPI07 I315
,
G19 1 + switch input ( ) key
GPI0 I302
,
15 1 POWER so t power switch input ( power ) key

Page 5Circuit Description
B1 AAU / B1 ANU / B1 AAY
8.4.2 Functions
Major unction o I315 are as ollows:
(1) Expansion o the display screen.
(2) Timing control or various signal types.
(3) Power-supply sequence (LCD panel).
8.5 I2C bus control
8.5.1 Related ports o I302
Port Pin No. I/O Si
g
nal name Function
P3.5 17 I IICCLK IIC bus clock
P3.4 16 I/O IICDATA IIC bus data
8.5.2 I2C-controlled unctions
The ollowing unctional controls are e ected by I2C.
(1) Control o EEPROM I305 or parameter setting.
(2) Control o audio preampli ier.
8.4 Control o de inition converter LSI I315
Pin No. I/O Si
g
nal name Function
R3 I IRQ gmZan1 interrupt signal
P1 O HCLK gmZan1 serial clock
P3, P4,
R1
,
R2
I/O HDATA gmZan1 serial data
P2 O HFS gmZan1 serial select
8.4.1 Ports related to control

Page 6 Circuit Description
B1 AAU / B1 ANU / B1 AAY
8.6 Power ON sequence
When the POWER switch is pressed, the POWER OFF signal is turned H. When this H potential is detected,
the CPU begins to establish the respective power supplies according to the sequence shown below.
POWER
LED
LVCC
(Audio_EN)
Panel_VCC
PCLK/DATA
Backlight_EN

Page 7Circuit Description
B1 AAU / B1 ANU / B1 AAY
8.7 Power OFF sequence
When the POWER switch is pressed while the power supply is ON, the POWER ON signal is turned H. When
this H potential is detected, the CPU begins to turn o the respective power supplies according to the sequence
shown below.
POWER
LED
LVC C
(Audio_EN)
Panel_VCC
PCLK/DATA
Backlight_EN

Page 8 Circuit Description
B1 AAU / B1 ANU / B1 AAY
Port Pin No. Signal Name Initial Setting Function Remark
~ NC ~ ~
P1.0 HDATA0 ~ gm5020 4bit inter ace data
P1.1 !HDATA1 ~ gm5020 4bit inter ace data
P1.2 "HDATA2 ~ gm5020 4bit inter ace data
P1.3 #HDATA3 ~ gm5020 4bit inter ace data
P1.4 $HCLK ~ gm5020 4bit inter ace Clock
P1.5 %HFS ~ gm5020 data Enable
P1.6 &Pand-EN H Panel VCC Enable
P1.9 'IIC-EN H IIC Enable
~ RST L Reset CPU Active H
P3.0  RXD H Receive data
~ NC ~ ~
P3.1 ! TXD H Transmit data
P3.2 " IRQ ~ gm5020 interrupt signal
P3.3 # PWR_SW ~ ON/OFF monitor power
P3.4 $ SDA H IIC Bus Data
P3.5 % SCL ~ IIC Bus Data Active L
P3.6 & NC ~ ~
P3.7 ' DDC_GND L Detect Dsub cable plug-in
~  XTAL2 ~ Crystal signal out
~  XTAL ~ Crystal signal in
~ GND ~ ~
~ ! NC ~ ~
P2.0 " NC ~ ~
P2.1 # LED GRN H LED Green ON / OFF
P2.2 $ LED AMB H LED Amber ON / OFF
P2.3 % MUTE H Audio MUTE
P2.4 & CUSP H Audio SUSP
P2.5 ' BACK_EN H Backlight Enable
P2.6 ! LVDS_ON H LVDS IC ON / OFF
P2.7 ! NC ~ ~
~! PSEN# H Program store enable
~!! NC ~ ~
~!" NC ~ ~
~!# EA# H External Access Enable
P0.7 !$ NC ~ ~
P0.6 !% NC ~ ~
P0.5 !& NC ~ ~
P0.4 !' NC ~ ~
P0.3 " NC ~ ~
P0.2 " NC ~ ~
P0.1 " NC ~ ~
P0.0 "! NC ~ ~
~"" VCC ~ VCC
8.8 List o CPU Pin Assignments

Circuit Description Index
B1 AAU / B1 ANU / B1 AAY
9. Power Board Operation Therory
9.1 Line ilter consists o C801, T801, C802, C803, C804. It eliminates high requency inter erence to meet EMIs
requirement.
9.2 Rec & Filter
Bridge diode D801 converts AC source into pulsed DC. This pulsed DC is smoothed and iltered by C805. R802
is an NTC ( negative thermal coe icient ) resistor, used to reduce inrush current to be within sa e range.
9.3 Power trans ormer :
T802 converts energy or square wave rom power source C805 to secondary side to generate +12V and +5V.
9.4 Output :
The square wave rom T802 is recti ied by D809, D810, then iltered by C817, C822 to generate +12V and +5V
respectively.
9.5 Driver :
Q803 drive T802 rom PWM control o I801 or power converted.
9.6 FB :
Negative eedback CKT consists o photo coupler I802 and adjustable regulator I803. It can maintain output
voltages +5V and +12V at a stable level.
9.79.7
9.79.7
9.7 PWM :PWM :
PWM :PWM :
PWM :
9.7.19.7.1
9.7.19.7.1
9.7.1 Start : When power is turned on, Q801 conducts due to bias from C805 and R805,R803. C807 is charStart : When power is turned on, Q801 conducts due to bias from C805 and R805,R803. C807 is char
Start : When power is turned on, Q801 conducts due to bias from C805 and R805,R803. C807 is charStart : When power is turned on, Q801 conducts due to bias from C805 and R805,R803. C807 is char
Start : When power is turned on, Q801 conducts due to bias from C805 and R805,R803. C807 is charged aged a
ged aged a
ged a
16 volt and a starting current about 0.3mA to pin 7 of I801. I801 starts to oscillate and outputs a pulse train16 volt and a starting current about 0.3mA to pin 7 of I801. I801 starts to oscillate and outputs a pulse train
16 volt and a starting current about 0.3mA to pin 7 of I801. I801 starts to oscillate and outputs a pulse train16 volt and a starting current about 0.3mA to pin 7 of I801. I801 starts to oscillate and outputs a pulse train
16 volt and a starting current about 0.3mA to pin 7 of I801. I801 starts to oscillate and outputs a pulse train
through pin 6 to drive Q803.through pin 6 to drive Q803.
through pin 6 to drive Q803.through pin 6 to drive Q803.
through pin 6 to drive Q803.
9.7.29.7.2
9.7.29.7.2
9.7.2 OPP : When Q803 turns on, C805 supplies a linearly increasing triangle current through the primary induc-OPP : When Q803 turns on, C805 supplies a linearly increasing triangle current through the primary induc-
OPP : When Q803 turns on, C805 supplies a linearly increasing triangle current through the primary induc-OPP : When Q803 turns on, C805 supplies a linearly increasing triangle current through the primary induc-
OPP : When Q803 turns on, C805 supplies a linearly increasing triangle current through the primary induc-
tance of T802 to the driver Q803, once the peak value of this current multiplied by R81tance of T802 to the driver Q803, once the peak value of this current multiplied by R81
tance of T802 to the driver Q803, once the peak value of this current multiplied by R81tance of T802 to the driver Q803, once the peak value of this current multiplied by R81
tance of T802 to the driver Q803, once the peak value of this current multiplied by R81 1 exceeds1 volt,1 exceeds1 volt,
1 exceeds1 volt,1 exceeds1 volt,
1 exceeds1 volt,
pulse train will be turn ofpulse train will be turn of
pulse train will be turn ofpulse train will be turn of
pulse train will be turn of f immediately to protect Q803, T802 from being burned out.f immediately to protect Q803, T802 from being burned out.
f immediately to protect Q803, T802 from being burned out.f immediately to protect Q803, T802 from being burned out.
f immediately to protect Q803, T802 from being burned out.
9.7.39.7.3
9.7.39.7.3
9.7.3 Regulation : If output voltage +5V goes up, the R terminal of I803 gets more bias, accordingly photoRegulation : If output voltage +5V goes up, the R terminal of I803 gets more bias, accordingly photo
Regulation : If output voltage +5V goes up, the R terminal of I803 gets more bias, accordingly photoRegulation : If output voltage +5V goes up, the R terminal of I803 gets more bias, accordingly photo
Regulation : If output voltage +5V goes up, the R terminal of I803 gets more bias, accordingly photo
transistor and photo diode flows more current. The voltage of pin 2 goes up too, making the pulse width oftransistor and photo diode flows more current. The voltage of pin 2 goes up too, making the pulse width of
transistor and photo diode flows more current. The voltage of pin 2 goes up too, making the pulse width oftransistor and photo diode flows more current. The voltage of pin 2 goes up too, making the pulse width of
transistor and photo diode flows more current. The voltage of pin 2 goes up too, making the pulse width of
pin 6 to become narrower. So the output voltage +5V will be pulled down to a stable value.pin 6 to become narrower. So the output voltage +5V will be pulled down to a stable value.
pin 6 to become narrower. So the output voltage +5V will be pulled down to a stable value.pin 6 to become narrower. So the output voltage +5V will be pulled down to a stable value.
pin 6 to become narrower. So the output voltage +5V will be pulled down to a stable value.
9.7.49.7.4
9.7.49.7.4
9.7.4 OVP : If +5V goes up too much, the induced voltage on pin 4 of T802 becomes larOVP : If +5V goes up too much, the induced voltage on pin 4 of T802 becomes lar
OVP : If +5V goes up too much, the induced voltage on pin 4 of T802 becomes larOVP : If +5V goes up too much, the induced voltage on pin 4 of T802 becomes lar
OVP : If +5V goes up too much, the induced voltage on pin 4 of T802 becomes lar ge also. Suppose that it isge also. Suppose that it is
ge also. Suppose that it isge also. Suppose that it is
ge also. Suppose that it is
over 18 volts, ZD801 conducts, pin 3 of I801 is pulled up over 1 volt. The pulse train at pin 6 goes down toover 18 volts, ZD801 conducts, pin 3 of I801 is pulled up over 1 volt. The pulse train at pin 6 goes down to
over 18 volts, ZD801 conducts, pin 3 of I801 is pulled up over 1 volt. The pulse train at pin 6 goes down toover 18 volts, ZD801 conducts, pin 3 of I801 is pulled up over 1 volt. The pulse train at pin 6 goes down to
over 18 volts, ZD801 conducts, pin 3 of I801 is pulled up over 1 volt. The pulse train at pin 6 goes down to
zero, shutting Q803 ofzero, shutting Q803 of
zero, shutting Q803 ofzero, shutting Q803 of
zero, shutting Q803 of f immediatelyf immediately
f immediatelyf immediately
f immediately..
..
.
9.7.59.7.5
9.7.59.7.5
9.7.5 SCP : If output terminal is short to ground, photo transistor does not conduct, hence Q806 does not conductSCP : If output terminal is short to ground, photo transistor does not conduct, hence Q806 does not conduct
SCP : If output terminal is short to ground, photo transistor does not conduct, hence Q806 does not conductSCP : If output terminal is short to ground, photo transistor does not conduct, hence Q806 does not conduct
SCP : If output terminal is short to ground, photo transistor does not conduct, hence Q806 does not conduct
eithereither
eithereither
either. Then oscillation of I801 is stop, shutting Q803 of. Then oscillation of I801 is stop, shutting Q803 of
. Then oscillation of I801 is stop, shutting Q803 of. Then oscillation of I801 is stop, shutting Q803 of
. Then oscillation of I801 is stop, shutting Q803 of f immediatelyf immediately
f immediatelyf immediately
f immediately..
..
.
Line
Filter
Rec. &
Filter Power
Transformer Outpur Rec. & Filter
PWM Driver
FB
B17AAU Power Board Block Diagram

Index Trouble Shooting
B17AAU / B17ANU / B17AAY
1. No display of screen (Screen is black, color of LED is amber) ----------------------------------------------------- 1
2. No hing displays on screen (Screen is black, color of LED is green) ---------------------------------------------- 2
3. Checking he back ligh uni --------------------------------------------------------------------------------------------- 5
4. Abnormal screen ---------------------------------------------------------------------------------------------------------- 6
5. Abnormal Au o adjus men ---------------------------------------------------------------------------------------------- 8
5.1 NO OSM display ----------------------------------------------------------------------------------------------------- 8
5.2 OSD Adjus problem ------------------------------------------------------------------------------------------------- 8
6. Abnormal plug and play opera ion ------------------------------------------------------------------------------------- 9
6.1 Abnormal DDC2 ------------------------------------------------------------------------------------------------------ 9
7. Checking he in erface circui of sync signal -------------------------------------------------------------------------10
7.1 Checking he con rol circui of horizon al sync pulse ---------------------------------------------------------- 10
7.2 Checking he con rol circui of ver ical sync pulse -------------------------------------------------------------- 10
8. Checking he resolu ion change IC movemen -----------------------------------------------------------------------11
9. No power on -------------------------------------------------------------------------------------------------------------- 12
10. Checking he DC/DC conver er circui -------------------------------------------------------------------------------- 13
11. Checking he opera ion of CPU ---------------------------------------------------------------------------------------- 14
12. Power board--------------------------------------------------------------------------------------------------------------- 15
Table of Contents

Trouble Shooting Page 1
B17AAU / B17ANU / B17AAY
1. No display of screen (Screen is black, color of LED is amber)
Does OSM display when you push
PROCEED button.
Yes
Check if the sync signal from Computer
is output and if the video cable is
connected normally.
No Preceed "No OSM display"section.
OK
Proceed "Checking the resolution change
IC movement" section.
NG Input the sync signal of computer, or
change the cable.
When a signal isn't
being inputted, it is
indicated with "VIDEO
INPUT". It is indicated
with "OUT OF RANGE"
at the time of the
frequency that it can't be
distinguished.

Page 2 Trouble Shooting
B17AAU / B17ANU / B17AAY
2. Nothing displays on screen (Screen is black, color of LED is green)
Is backlight lit?
OK
Does computer output RGB video signals?
NG Refer "Checking the backlight unit" section
OK
Check OSM menu is displayed on screen
when you push the "PROCEED" key.
NG
1) Change pattern of video signal output on the
host.
2) Reconnect the video cable.
3) Change the video cable.
Check the video cable for failure. Check the host for
output signal with all black only.
OK NG
Proceed "Abnormal screen" section.
Check if the LCD video signal cable is connected
between the MAIN PWB and LCD module.
OK NG
Next Page
Failure Point
The Cable is disconnected.

Trouble Shooting Page 3
B17AAU / B17ANU / B17AAY
Continue
Check if the voltage on I323 pin 3 that
is high level DC at 5V.
Check the 3.3 V power are supplied on I323, pin 2.
OK
NG
OK NG
Failure point
1) Printed wire broke between P310 pin 7, 8 and
and I323.
2) Check power board.
Failure point
I323 Failure
Is a dot clock being outputted under the
condition that a LCD module is
connected to L322 pin 2?
OK NG
Failure point
1) I315 failure
2) Printed wire broke between I315 and L322 pin 2.
Check the H-sync pulse of negative polarity
is output on RN314 pin 8 at TTL level.
OK NG Failure point
1) I315 failure
2) Printed wire broke between I315 and RN314 pin 8.
Check the V-sync of negative polarity
are output on RN314 pin 7.
OK NG
Next Page
Failure point
1) I315 failure
2) Printed wire broke between I315 and RN314 pin 7.

Page 4 Trouble Shooting
B17AAU / B17ANU / B17AAY
Continue
Check the data enable of positive polarity are output on RN314 pin 6.
OK NG
Failure point
1) I315 failure.
2) Printed wire broke between I315 and RN314 pin 6.
Check the data signal output on I315 R, G, B
data pin.
OK NG
Failure point
1) I315 failure.
Failure point
1) The cable broke between P304 and LCD
module.
2) LCD module failure.
Check I319, I320 all LVDS signal pins.
OK NG
Failure point
1) I319, I320 failure.
2) Printed wire broke between I319, I320 and P307.

Trouble Shooting Page 5
B17AAU / B17ANU / B17AAY
3. Checking the back light unit
Is +12V supplied to inverter PWB?
OK NG Failure point
1) Inverter cable disconnection.
2) Power board failure.
Check the BKLT_EN signal of the rectangle input P310 pin 2 at TTL high level
OK
NG Is a "H" level being output in the TTL level from I302 pin 29
Or, is BKLT_EN signal of the rectangle being output?
NG
Failure point
Printed wire broke between
I302 pin 29 and R326.
Check the PWM signal of the input from I315 pin M4 (R374 pin 2) is a PWM signal.
OK NG Failure point
1) Printed wire broke between
I315 pin M4 and R374 pin 2.
2) I315 failure.
Failure point
1) Inverter cable disconnection.
2) Inverter of LCD module failure.

Page 6 Trouble Shooting
B17AAU / B17ANU / B17AAY
OK NG
Failure point
1) No R, G and B video signal output from host computer. Check
computer
2) Video signal cable disconnection.
OK NG
Check the R, G, B video signal from computer input on
D-Sub R, G, B connector.
Check the R, G, B input signals on I315 pin E1, D2, C1
respectively that their level is 0.7Vp-p maximum.
Is the pulse of the TTL level being output to I319, I320
from the data line of I315?
Failure point
In the case of the Red signal. (A Green and Blue signal is the same
path, too.)
1) Printed wire broke between D-Sub(R) and I315 pin E1.
2) R339 short.
3) C359 open.
4) R337 open.
OK NG Failure point
1) Printed wire broke between I315 data line and I319, I320.
2) I315 failure.
Check the negative horizontal sync pulse output to
RN314 pin 8 from I315 pin F20 at TTL level.
OK NG
Failure point
1) Printed wire broke between I315 pin F20 and RN314 pin 8.
2) I315 failure
Check the negative vertical sync pulse output to RN314
pin 7 from I315 pin F19 at TTL level.
OK NG
Check the positive DE pulse output to RN314 pin 6 from
I315 pin F18 at TTL level.
OK NG
Check the SHFCLK OUTPUT to L322 pin 2 from I315 pin
G20 at TTL level.
OK NG
Next Page
Failure point
1) Printed wire broke between I315 pin G20 and L322 pin 2.
2) L321 open
3) C583 short
4) C590 short
5) L322 short
6) I315 failure
Failure point
1) Printed wire broke between I315 pin 73 and RN314 pin 7.
2) I315 failure
Failure point
1) Printed wire broke between I315 pin F18 and RN314 pin 6.
2) I315 failure
4. Abnormal screen

Trouble Shooting Page 7
B17AAU / B17ANU / B17AAY
OK NG
Continue
Check I319, I320 all LVDS signal pins.
Process "Checking the resolution change IC movement"
section.
Failure point
1) I319, I320 faulure.
2) Printed wire broken between I319, I320 and P307.