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