Text preview for : LITEON J15AAC.pdf part of LITEON J15AAC LCD service manual
Back to : LITEON J15AAC.rar | Home
Service Manual
15-inch LCD Monitor
J15AAC/J15ANC (MRT)
Service Manual Versions and Revision
No. Version Release Date Revision
1. 1.0 July 3, 2002 Original release
Copyright Trademarks
Copyright 2002 LiteOn Technology Corp. LiteOn is a registered trademark of LiteOn
Technology Corp.
All Rights Reserved
All other trademarks are the property of their
This manual may not, in whole or in part, be
respective owners.
copied, photocopied, reproduced, translated, or
converted to any electronic or machine readable
form without prior written permission of LiteOn
Technology Corp.
J15AAC/J15ANC (MRT) Service Manual.
Printed in Taiwan.
J15AAC/J15ANC (MRT)
Table of Contents
1. Audio circuit ---------------------------------------------------------------------------------------------------------------------------- 1
1.1 Audio input ------------------------------------------------------------------------------------------------------------------------- 1
1.2 Audio output ----------------------------------------------------------------------------------------------------------------------- 1
2. Power supply ---------------------------------------------------------------------------------------------------------------------------- 1
3. On-screen circuit ----------------------------------------------------------------------------------------------------------------------- 2
4. Video input circuit --------------------------------------------------------------------------------------------------------------------- 2
5. Definition converter LSI peripheral circuit ------------------------------------------------------------------------------------- 2
6. System reset, LED control circuit ------------------------------------------------------------------------------------------------- 2
7. E2PROM for PNP ---------------------------------------------------------------------------------------------------------------------- 3
8. E2PR OM ---------------------------------------------------------------------------------------------------------------------------------- 3
9. CPU circuit ------------------------------------------------------------------------------------------------------------------------------ 3
9.1 Dection of POWER switch status --------------------------------------------------------------------------------------------- 3
9.2 Display mode identification ---------------------------------------------------------------------------------------------------- 3
9.3 User control ------------------------------------------------------------------------------------------------------------------------ 4
9.4 Control of identification converter LSI (IC307) -------------------------------------------------------------------------- 5
9.5 I2C bus control --------------------------------------------------------------------------------------------------------------------- 5
9.6 Po wer ON seq uence -------------------------------------------------------------------------------------------------------------- 6
9.7 Po wer OFF sequence ------------------------------------------------------------------------------------------------------------- 7
10. In verter------------------------------------------------------------------------------------------------------------------------------------- 8
Index Circuit Description
J15AAC/J15ANC (MRT)
1. Audio circuit (Circuit diagrams Interface PWB)
1.1 Audio input
The audio signal input received from the audio input terminal (JK011) is applied to the amplifier I309 of 4 (L-
CH) and 9 (R-CH) through the low-pass filter consisting of R372, R373, R374, R375, C374 and C375.
In this amplifier, controls of Volume and mute are conducted. The audio signal controlled at the pin 6 determines
the attenuation of output of the amplifiers. Since then, the signal is output to the jack P303.
1.2 Audio output
The audio signal is output from the jack output terminal (JK012) of the Audio Jack board to the internal speaker
system.
2. Power supply (Circuit daigrams Power PWB)
2.1 Line filter consists of C801, T801, C802, C803, C804. It eliminates high frequency interference to meet EMI's
requirement.
2.2 Rec & Filter :
Bridge diode D801 converts AC source into pulsed DC. This pulsed DC is smoothed and filtered by C805.
R802 is an NTC ( negative thermal coefficient ) resistor, used to reduce inrush current to be within safe range.
2.3 Power tran sformer :
T802 converts energy for square wave from power source C805 to secondary side to generate +12V and +5V.
2.4 Output :
The square wave from T802 is rectified by D809, D810, then filtered by C817, C822 to generate +12V and
+5V respectively.
2.4.1 A 5V power supply for LCD module, CPU and logic i s generated from the p ower source.
2.4.2 I310 : 3-terminal regulator
A 3.3V power supp ly for I306 analog is generated from the 5V source.
2.4.3 I310 : 3-terminal regulator
A 3.3V power suppl y for I306 digital is generated from the 5V source.
Q303, Q304 ON/OFF control for LCD Module
ON/OFF co ntrol is performed for power ON/OFF and also for t he power saving sequence.
2.5 Driv er :
Q803 drive T802 from PWM control of I801 for p ower converted.
2.6 FB :
Negative feedback CKT consists of photo coupler I802 and adjustable regulator I803. It can maintain output
voltages +5V and +12V at a stable level.
2.7 PWM :
2.7.1 Start : When power is turned on, R805, R803 conducts due to bias from C805. C807 is charged a 16
volt and a starting current to pin 7 of I801. I801 starts to oscillate and outputs a pulse train
through pin 6 to drive Q803.
2.7.2 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 R811 exceeds1 volt, pulse train
will be shut down immediately to protect Q803, T802 from being burned out.
Circuit Description Page 1
J15AAC/J15ANC (MRT)
2.7.3 Regulation : If output voltage +5V goes up, the R terminal of I803 gets more bias, accordingly photo transis
tor 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.
2.7.4 OVP : If +5V goes up too much, the induced voltage on pin 4 of T802 becomes large 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 to
zero, shutting Q803 off immediately.
2.7.5 SCP : If output terminal is short to ground, photo transistor does not conduct, hence Q806 does not conduct
either. Then oscillation of I801 is stop, shutting Q803 off immediately.
Power Board Block Diagram
Rec.
Line Filter Power Output Rec. & Filter
&
Transformer
Filter
PWM Driver
FB
3. On-screen circuit (Circuit diagrams Interface PWB)
I307 (Mascot VZ) Embeded function.
On-screen menu screen is established and the resultant data are output from I307 (Circuit diagram Interface PWB
, Mascot VZ).
4. Video input circuit (Circuit diagram Interface PWB)
The AC-coupled video signal is used to clamp the black level at 0V).
5. Definition converter LSI peripheral circuit (Circuit diagram Interface PWB)
I307 Mascot VZ is the definition converter LSI.
The analog R, G, B signal input entered from the video input circuit is converted into the digital data of video
signal through t he incorporated A/D co nverter. B ased on thi s conversi on, this device performs interpo lation
during pixel extension. The source voltage for this device is 3.3V and the system clock frequency is 12MHz.
The withstand voltage level for the input signal voltage is 3.3V and 5V.
6. System reset, LED control circuit (Circuit diagram Interface PWB)
6.1 System reset
System reset is performed by detecting the rising and falling of the 5V source voltage at I301.
6.2 LED control circuit
Green / amb er is lit with the control signal of the LED GREEN and LED AM BER signal pin 29, 2 8 from I302
(Circuit diagram Interface PWB).
Page 2 Circuit Description
J15AAC/J15ANC (MRT)
7. E2 PROM for PnP (Circuit diagram Interface PWB)
Data transfer between I305 and host.
There are two forms of communications protocal. In both, display capab ilities are retrieved by the system software
during the boot-up and configuration time.
For the PC platform, this soft ware layer is defined in th e VESA BIOS Extension / Di splay Data Chann el, DDC2,
standard.
8. E2 PROM (Circuit diagram Interface PWB)
Data transfer between I304 (24LC16B) and I302 (Circuit diagram Interface PWB page 2/8) is effected through
the IIC bus SC L (pin 9) and SDA (pin 8) o f I302. The data to be transferred to each device are stored in I304.
l I302 control data.
l OSD related setting data.
l Other control data for service menu.
9. CPU circuit (Circuit diagram Interface PWB)
I302 (8051) is microcontroller with ROM in terface (I304).
The source voltage for the device is 5V and the system clock frequency is 12MHz.
9.1 Detection of POWER switch status
The I302 identifies the ON status of the two power supplies. The identification is made when the power supply is
turned off. For example, if the power supply is turned off with the POWER switch, the POWER switch must be
turned on when activating the power supply again. If t he power supply is tu rned off by pulling ou t the power
cord , then this p ower su pply can be tu rned o n by co nnectin g the power cord, wi thout p ressin g the POWER
switch.
9.2 Display mode identification
9.2.1 Functions
(1) Display mode identification
l The display mode of input signal is identified based on Table 1, and according to the frequency and polarity
(HPOL, VPOL) of horizontal or vertical sync signal, presence of the resolution or vertical sync signal, and the
discrimination sign al (HSYNC_DETECT, VSYNC_DETECT).
l When the mode has been identified through the measurement of horizontal and vertical frequencies, the total
number of lines is determined with a formula of " Horizontal frequency / Vertical frequency = Total number
of li nes. "Final identification can be made by exami ning the coincidence of the obtained figure wit h the
number of lines for the mode i dentified from the frequency.
l When the detected frequency if the sync signal has changed, the total number of lines should be counted even
throug h it is regi stor identified frequen cy in the same mode. Then, it is necessary to examine wheth er the
preset value for the vertical display position has exceeded the total number of lines. If exceeded, a maximum
value should be set up, which does not exceed the vertical display position.
(2) Out-of -range
This out-of-range mode is assumed when the frequency of the horizontal / vertical signal is as specified below.
l Vertical frequency : Below 56.2Hz or above 76Hz
l Horizontal frequency : Belo w 31.5 KHz or above 61 KHz
(3) Power save mode
The power save mode is assumed when the horizontal / vertical signals are as specified below.
l If there is no horizontal sync signal input.
l If there is no vertical sync signal input.
Circuit Description Page 3
J15AAC/J15ANC (MRT)
l If the horizontal sync signal is outside the measuring range of Mascot VZ.
l If the vertical sync signal is outside the measuring range of Mascot VZ.
Table 1
Mode No Resolution H-freq Band Width Polarity
(KHz) (MHz) H V
1. 247 VGA 720 x 350 70Hz 31.47 28.322 + -
2. 102 VGA 720 x 400 70Hz 31.47 28.322 - +
3. 103 VGA 640 x 480 60Hz 31.47 25.175 - -
4. 182 MAC 640 x 480 66Hz 35 30.24 - -
5. 173 VESA 640 X 480 72Hz 37.86 31.5 - -
6. 109 VESA 640 X 480 75Hz 37.5 31.5 - -
7. 104 VESA 800 x 600 56Hz 35.16 36 + +
8. 116 VESA 800 x 600 60Hz 37.88 40 + +
9. 110 VESA 800 x 600 75Hz 46.88 49.5 + +
10. 117 VESA 800 x 600 72Hz 48.08 50 + +
11. 108 MAC 832 x 624 75Hz 49.72 57.283 - -
12. 118 VESA 1024 x 768 60Hz 48.36 65 - -
13. 217 SUN 1024 x 768 65Hz 52.45 70.49 - -
14. 157 VESA 1024 x 768 70Hz 56.48 75 - -
15. 141 VESA 1024 x 768 75Hz 60.02 78.75 + +
Attention :
1. When resolution beyond 1024 x 768 is inputted, resolution is lowered with Down scaling to 1024 x 768, and
indicated, and OSD should indicate OUT of Range.
9.3 User Control
General Key Description
A T
UO
MN
E U
1 2 3 4
1. Select MENU: To exit and enter OSD menu.
2. Select : To move downward in the OSD Item.
3. -: To decrease the value of the parameter in the OSD, which has been selected for adjustment.
-: Choose the previous OSD MENU page.
AUTO: Act as AUTO adjustment hot key when OSD is not displayed.
4. +: To increase the value of the parameter in the OSD, which has been selected for adjustment.
+: Choose the next OSD MENU page.
: Act as Audio Mute hot key when OSD is not displayed.
Page 4 Circuit Description
J15AAC/J15ANC (MRT)
9.3.1 Related ports of I302
Port Pin No. I/O Signal name Function Remarks
P2.1 25 I/O DOWN Down switch input ( DOWN ) key
P2.0 24 I/O MENU Menu Switch input (MENU ) key
P.2.3 27 I/O LEFT/AUTO - switch input ( - )hot key
P.2.2 26 I/O RIGHT/MUTE + switch input ( + )hot key
9.3.2 Functions
Control is effected for the push-switches to be used when the user changes the parameters, in order to modify the
respective setting values. Whether the switch has been p ressed is identified with the switch input l evel that is
turned "L".
Each parameter is stored in the EEPROM, the contents of which are updated as required.
9.4 Control of definition converter Mascot VZ (I307).
9.4.1 Ports related to control
Pin No. I/O Signal name Function
157 I/O SDA Mascot VZ serial data
156 I/O SCL Mascot VZ serial clock
159 O IRQ Mascot VZ Interrupt to host
9.4.2 Functions
Major function of I307 are as follows:
(1) Expansion of the display screen.
(2) Timing control for various signal types.
Circuit Description Page 5
J15AAC/J15ANC (MRT)
9.6 Power ON sequ ence
9.6.1 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
PPWR
DOTCLK
INV_EN
LED
DATA
9.6.2 Power sequence for panel requirement.
Power sequence
VDDD->VEEG,VDDA,VCOM->VDDG
5 ms¡Øt1
10ms ¡Øt2
t3 ¡Ø100ms
90%
VDDD
90%
VDDA,VCOM,VEEG
90%
DATA
VDDG
t1
t2
Notes: VDDA,VCOM,VEEG
t3 power sequence don't
care.
Page 6 Circuit Description
J15AAC/J15ANC (MRT)
9.7 Power OFF seq uence
When the POWER switch is pressed while the power supply is ON, the POWER ON signal is turned "H". When
tshown below.his "H" potential is detected, the CPU begins to turn off the respective power supplies according
to the sequence
POWER
PPWR
DOTCLK
INV_EN
LED
DATA
Circuit Description Page 7
J15AAC/J15ANC (MRT)
10. Inverter
This unit operates on an output voltage of 15V from power source.
10.1 Regulator: Q101 get a +5VDC for I102 power supply.
10.2 UVP: Q106 turns off when the Vin is under 14V. Then pin 3 of I102 is pulled low and inverter off immediately.
That is the under voltage protection.
10.3 Control IC: I102 (OZ960S)
10.3.1 Enable : When pin 3 of I102 is over 1.5V, I102 works. If it is under 1.5V, I10 2 turns off.
10.3.2 OSC: When I102 enabled, R108/C115 (pin 17/pin18 of I102) determine the operating frequency.
10.3.3 SST: C104 (pin 4 of I102) provides soft start function.
10.3.4 Ignition: R109 (pin 8 of I102) provides higher operating frequency for more striking voltage until regulation
of feedback of lamp current. C103 (pin 1 of I102) determine the striking time.
10.3.5 Dimming control: The divided voltage of R106/R105/R104 control the duty pulse of burst-mode to drive Q105
and perform a wide dimming co ntrol for the CCFL. The burst-mode frequency is determined by C116.
10.3.6 Regulation: Pin 9/pin 10 of I102 provide regulation of the CCFL current from feedback. The non-inverting
reference (pin 10 of I102) is at 1.25 V nominal.
10.4 Protection: Open-lamp protection in the ignition period is provided through both pin1 and pin 2 of I102.
Removal of the CCFL during normal operation wil l trigger Q104 to turns on and shuts off the inverter. This
is latch function.
10.5.1Output drivers: The configuration prevents any shoot-through issue associated with bridge-type power
conversion applications. Adjusting the overl ap conduction between I101 P-MOSFET and I103 N-MOSFET,
I101 N-MOSFET and I103 P-MOSFET, the CCFL curren t regulation is achieved.
10.5.2 Full-bridge switching/Transformer: I101/I103 /C123/C125/T101 compose full-bridge switching to
convert DC int o AC for driver the CCFL.
10.6 Detection: C124/C119/CR102 detect the output voltage and ensure a rated voltage by pin2 of I102. Q102/Q103
ensure not a o pen-lamp.
10.7 Feedback: CR101/R120/R121/D108 sense the lamp current for negative feedback and regulation. The divided
voltage on R121 will be at 1.25V.
Inverter Board Block Diagram
VCC
Regulator
VDD
Control IC : OZ960 Full-bridge switching Lamp
Transformer
ON / OFF U.V.P. Enable Output driver
OSC Protection Detection
SST Ignition
Brightness Dimming
Regulation Feed back
control control
Page 8 Circuit Description
J15AAC/J15ANC (MRT)
Table of Contents
1. No display of screen (Screen is black, color of LED is amber) ----------------------------------------------------------- 1
2. Nothing displays on screen (Screen is black, color of LED is green) ---------------------------------------------------- 2
3. Checking the back light unit -------------------------------------------------------------------------------------------------------- 5
4. Abnormal screen ----------------------------------------------------------------------------------------------------------------------- 6
5. No OSD display ------------------------------------------------------------------------------------------------------------------------ 7
6. Abnormal plug and play operation ------------------------------------------------------------------------------------------------ 8
7. Checking the interface circuit of sync signal ----------------------------------------------------------------------------------- 9
7.1 Checking the control circuit of horizontal sync pulse ------------------------------------------------------------------- 9
7.2 Checking the control circuit of vertical sync pulse ---------------------------------------------------------------------- 9
8. Checking the resolution change IC movement ------------------------------------------------------------------------------- 10
9. No power on -------------------------------------------------------------------------------------------------------------------------- 11
9.1 No power o n (I) ----------------------------------------------------------------------------------------------------------------- 11
9.2 No power on (II) ---------------------------------------------------------------------------------------------------------------- 12
10. Checking the DC/DC converter circuit ---------------------------------------------------------------------------------------- 13
11. Checking the operation of CPU -------------------------------------------------------------------------------------------------- 14
12. Checking the audio circuit --------------------------------------------------------------------------------------------------------- 15
13. Checking inverter board circuit -------------------------------------------------------------------------------------------------- 16
Index Index
J15AAC/J15ANC (MRT)
1. No display of screen (Screen is black, color of LED is amber)
Does OSD display when
you push key button.
When a signal isn't
being inputted, it is
indicated with "NO No
SIGNAL INPUT". It is Proceed "No OSD display"section.
Yes
indicated with "OUT OF
RANGE" at the time of
the frequency that it
can't be distinguished.
Check if the sync signal from Computer
is output and if the video cable is
connected normally.
Input the sync signal of computer, or
NG
OK change the cable.
Proceed "Checking the resolution change
IC movement" section.
Trouble Shooting Page 1
J15AAC/J15ANC (MRT)
2. Nothing displays on screen (Screen is black, color of LED is green)
Is backlight lit?
NG Refer "Checking the backlight unit" section
OK
Check the video cable for failure. Check the host for
Does computer output RGB video signals?
output signal with all black only.
1) Change pattern of video signal output on the
host.
NG 2) Reconnect the video cable.
OK 3) Change the video cable.
Check OSD menu is displayed on screen
when you push the "MENU" key.
NG Next Page
OK
Proceed "Abnormal screen" section.
Page 2 Trouble Shooting
J15AAC/J15ANC (MRT)
Continue
Check the 3.3 V power are supplied on I313 pin 2.
Check if the voltage on I313 pin1 that
NG
is high level DC at 5V.
Failure point
NG
OK OK 1) Printed wire broke between P301 and I313
Failure point
I313 Failure
1) Check +18V / +3.6V / -6V on P307.
NG Refer "Checking the panel power circuit"
2) Check +9.2 V on P308.
OK
Is a dot clock being outputted under the
condition that a LCD module is connected to
P308 pin 3?
Failure point
NG
OK 1) I307 failure
2) Printed wire broke between I307 and P308 pin 3.
Check the pulse of POL / HMS2 / HMS1 / LP /
STH are output on P308 pin 44, 45, 46, 47,
48 at TTL level.
Failure point
NG 1) I307 failure
OK
2) Printed wire broke between I307 and P308 pin 44,
45, 46, 47, 48.
Check the CLKV/STV1 pulse are output on
P307 pin 7, 8.
Failure point
NG
OK 1) I307 failure
2) Printed wire broke between I307 and P307 pin 7, 8.
Next Page
Trouble Shooting Page 3
J15AAC/J15ANC (MRT)
Continue
Check the data signal output on P307 and
P308 R, G, B data pin.
Failure point
NG 1) I307 failure.
OK
2) Printed wire broke between I307 and P307 , P308
data line
Failure point
1) The cable broke between P307 , P308
and LCD module.
2) LCD module failure.
Page 4 Trouble Shooting
J15AAC/J15ANC (MRT)
3. Checking the back light unit
Is +15V supplied to P803
pin 3, 4 to inverter PWB?
Failure point
NG
OK
Inverter cable disconnection.
Check the INV_EN signal on R390 is TTL high level
Is a "H" level being output in the TTL level from I307 pin 141
NG
Or, is INV_EN signal being output?
OK NG
Failure point
Printed wire broke between
I307 pin 141 and P301 pin 6
Check the PWM signal of the input from I307 pin 146 is a BRI signal
Failure point
NG Printed wire broke between
OK
I307 pin 146 and P301 pin 5.
Failure point
1) Inverter cable disconnection.
2) Inverter of LCD module failure.
Trouble Shooting Page 5
J15AAC/J15ANC (MRT)
4. Abnormal screen
Check the R, G, B video signal from computer input on
D-Sub R, G, B connector.
Failure point
NG 1) No R, G and B video signal output from host computer. Check
OK
computer
2) Video signal cable disconnection.
Check the R, G, B input signals on I307 pin 59, 53, 47
respectively that their level is 0.7Vp-p maximum.
Failure point
In case of the Red signal. (A Green and Blue signal is the same
NG path, too.)
OK
1) Printed wire broke between D-Sub(R) and I307 pin 59.
2) R328 short.
3) C383 open.
4) R327 open.
Is the pulse of the TTL level being output to P307, P308
from the data line of I307?
Failure point
NG
OK
1) Printed wire broke between I307 data line and P307, P308
2) I307 failure.
Check pulse of POL/HMS2/HMS1/LP/STH are output to
P308 pin 44, 45, 46, 47, 48 at TTL level.
Failure point
NG 1) Printed wire broke between I307 and P308 of control line.
OK
2) LZ301~LZ312 open or RP303~RP314 open.
3) CN301~CN312 short
Check the pulse of CLKV/STV1 are output to P307
pin 7, 8.
Failure point
NG
OK 1) Printed wire broke between I307 and P307 of control line.
2) R414, R415 open
3) C360, C361 short
Check the CLKH OUTPUT to P308 pin 3 from I307 pin 78
at TTL level.
Failure point
NG 1) Printed wire broke between I307 pin 78 and P307 pin 39.
OK 2) FB314 open
3) FB313 open
4) C368 short
5) C367 short
Process "Checking the resolution change IC movement"
section.
Page 6 Trouble Shooting
J15AAC/J15ANC (MRT)
5. NO OSD display
Confirm the MENU key is pressed at that moment.
Failure point
NG
1) Function key is destroyed.
OK 2) FB341 open.
3) RP302 open.
Proceed "Checking the resolution change IC movement" section.
Trouble Shooting Page 7
J15AAC/J15ANC (MRT)
6. Abnormal plug and play operation
Confirm the input of serial clock on I305 pin 6 SCL at TTL level.
NG Failure point
I305 failure.
OK
Failure point
1) The video cable may have failed or may not to have connections for DDC.
2) Between I306 pin 6 and P306 pin 12 may have failed.
3) FB301, R320 open.
4) Cable failure.
Confirm the input of serial data on I305 pin 5 SDA at TTL level.
Failure point
NG
I305 failure.
OK
Failure point
1) The host machine isn't communicating in DDC2 mode.
2) The video cable may have failed or may not to have connections for DDC.
3) Between I305 pin 5 and P306 pin 11 may have failed.
4) FB302, R321 open.
5) Cable failure.
Page 8 Trouble Shooting
J15AAC/J15ANC (MRT)
7. Checking the interface circuit of sync signal
7.1 Checking the control circuit of horizontal sync pulse
Check the horizontal sync signal on I306
pin 11 and pin 8 TTL level.
Failure point
NG
1) Video cable may have failed.
OK 2) Printed wire broke between P306 pin 4
and I306 pin 11.
3) FB311, R334 open
Process "Checking the resolution change IC
movement" section.
7.2 Checking the control circuit of vertical sync pulse
Check the vertical sync signal on I306 pin 3
and 6 TTL level.
Failure point
NG
OK 1) Video cable may have failed.
2) Printed wire broke between P306 pin 3 and I306 pin 3.
3) FB310, R330 open
Process "Checking the resolution change IC
movement" section.
Trouble Shooting Page 9
J15AAC/J15ANC (MRT)
8. Checking the resolution change IC movement
Is there +3.3V supply on I307 pin 1, 14, 32, 33, 36, 71, 85, 95, 105, 115, 125, 135, 144
NG Proceed "Checking the DC/DC converter circuit section".
OK
Is 12MHz clock input to I307 pin 73
at TTL level?
Is 12MHz clock output from X302
NG at TTL level?
Failure point
OK NG
OK X302 failure
Failure point
Print wire broke between X302 and
I307 pin 73.
Is +5.0V supplied to I307 pin 155 at
high level?
Check the output of 5.0V "H" pulse
NG
OK from I301 pin 6.
NG Is 5.0V supplied to I301 pin 7?
Failure point
I307 failure OK
NG Failure point
OK
Power source
Failure point
Failure point
Print wire broke between I301 pin 6
I301 failure
and I307 pin 5.
Page 10 Trouble Shooting
J15AAC/J15ANC (MRT)
9. No power on
9.1 No power on (I)
Check output voltage +5V,
+15V is right or not.
Yes It is not power board
No problem.
Check power switch is turn on
or not.
No Turn switch on.
Yes
Check power cord ( P801), Signal cable
(P302),P802, P803
is connected right or not.
No Connect it right.
Yes
Check C805 is about DC
140V-330V or not.
No Check F801, D801, P801
Yes and repair them.
Check C807 is over
10V or not.
No Check R805, R803, ZD802, Q801,
Yes I801 and repair them.
Check pin 6 of I801 have
same pulse or not.
Check peripheral components
No of I801 and repair them.
Yes (e.g. Q805, Q806)
Check pin 3 of T802 have
same pulse or not.
No Check Q803, R813, R814, D806
Yes , R812 and repair them.
Check peak voltage of R811 triangle
pulse is up to 1 volt or not.
No Check D804, R807 and
Yes repair them.
Check D809, D810, C816, C821, T802
have same short circuit, or the output
+5V, +15V is over load.
Yes Repair them.
No
Check feedback circuit around I802,
I803 and the other components
and repair them.
Trouble Shooting Page 11
J15AAC/J15ANC (MRT)
9.2 No power on (II)
Check the + 5V power is supplied
from power source.
NG Failure point
OK Power source failure.
Is LED turned on in amber
momentarily when a power button is
pushed?
NG Failure point
OK Power source failure.
Proceed "Checking the resolution
change IC movement".
Page 12 Trouble Shooting
J15AAC/J15ANC (MRT)
10. Checking the DC/DC converter circuit
Check the output of 3.3V line voltage
from I313 pin 2.
Is the output FB318 being inputted
NG
to I313 pin 3.
NG Failure point
OK OK Printed wire broke between I313
pin 3 and output of FB318.
Failure point
I313 failure
Failure point
Printed wire broke between I313 pin 2 and I307 power supply pin.
Trouble Shooting Page 13
J15AAC/J15ANC (MRT)
11. Checking the panel power circuit
11.1
Check the output of -6V, +18V,
+9.2V line voltage on R394, FB343,
FB332.
NG Is the PWM wave on pin 5 of I311.
NG Check the output voltage of +5V on
pin 6 of I311
Failure point
OK OK NG
OK 1. F301 open
2. Q309 failure
Failure point
I311 failure
Failure point
D321, D322, D326, D324, D323 failure
Failure point
1) Printed wire broke between R394, FB343, FB332, P307 and P308.
2) TL431, C429, C427, C459, C443 failure
11.2
Check the output of +3.6V on
FB333.
NG Is the input voltage of +9.2V on
OK Q312 collector
Failure point
Printed wire broke between OK NG Process above item 11.1
FB333 and P307.
Check adjustable voltage of
+3.0V~+4.0V on pin 1 of I312
NG Check +3.0V~+4.0V on pin 3 of I312
Failure point
NG
OK OK 1) D325, C454 failure
2) R398, R401 open
Failure point
I312 failure
Failure point
Q312, Q313 failure
Page 14 Trouble Shooting
J15AAC/J15ANC (MRT)
12. Checking the audio circuit
Is a cable with the
host PC connected?
NG Failure point
OK
Audio cable disconntction.
Aren't the setups of the
host PC a minimum and off?
NG Failure point
OK
The setup of the host PC is changed.
Is correct output waveform
being inputted from JK011
pin 2, 3 of the host PC?
NG Failure point
OK Audio cable disconntction.
Is the waveform which is the
same as JK011 being
inputted to I309 pin 4, 9?
NG Failure point
1) Printed wire broke between P302 pin 1, 3 and I309 pin 4, 9.
OK 2) R372, R373 open.
3) R374, R375 short.
4) C374, C375 open.
Is output wavefrom being
outputted in I309 pin 14, 17?
NG
OK Is 14V supplied to I309 pin 15, 16?
NG
Proceed section 9.1 "No power on".
Failure point
OK
1) Speaker cable disconnection
2) Speaker failure
Is mute/STD-BY low level at pin 11,
pin 12.
NG Proceed section 11 "Checking
OK the resulution change IC movement".
Is Variable DC volume
control at pin 6.
NG Proceed section 11 "Checking
OK the resulution change IC movement".
Failure point
I309 failure.
Trouble Shooting Page 15
J15AAC/J15ANC (MRT)
13. Checking inverter board circuit
Check Vin pin is around 15.5V.
On/off pin is over 2V.
Brightness pin is between 0V and 3.7V.
NG
OK It is not inverter problem.
Check pin 5 of I102 is 5V.
NG Check Q101, D101, D104 and repair
OK
them.
Check CN102, CN103 is connected
right.
NG Check CCFL and repair them.
OK
Check pin 3 of I102 is over 2V.
NG Check Q106, D110 and repair them.
OK
Check pin 18 of I102 is triangle
pulse.
NG Check C115, R108, I102 and repair
OK them.
Check pin 4 of I102 there is soft start
edge up to 4V and pin 11, 12, 19, 20
there is some pulse output.
Repair I102.
NG
OK
Check pin 2 of I102 there is up to 2V
from output detection.
OK Check R120, D108, R116, CR101
NG and repair them.
Check full-bridge (I101, I103, D102,
D103, C123) work right.
Repair them.
NG
OK
Check transformer (T101) work right.
NG Repair them.
OK
Check detection (C124, C118, C126,
CR102, CR103 and like those) work
right and repair them.
Page 16 Circuit Description
J15AAC/J15ANC (MRT)
1. Recommended Parts List
Note: 1. The components identified by " " mark are critical for X-ray safety. Replace these with
only the same parts specified.
2. If you have spare parts need, please check BOM to get the last release part number of flash
ROM and related information.
No. Location Part Number Description
1 I301 6444006108 IC MOS M51953AFP 8P SOP
2 I307 6447000606 IC ASIC MASCOT VZ 160PIN PQFP
3 I302 6448015558 IC CPU/PROM P89C51RD 44P PLCC
4 I304 6448016508 IC 24LC16B 8P SOP MICROCHIP
5 I305 6448018208 IC 24LC02B 8P SOP
6 I306 6446006218 IC 74LVC14 14P TSSOP
7 I311 6442033608 IC LM2622 8PIN MSOP
8 I312 6442033708 IC TL062CDT 8P 508
9 I313 6442023326 IC LINEAR AIC1084 33CM 3P T026
10 I315 6444010808 IC FDS9435A 8P S08
11 Q312 6422007218 TR NPN MMBT2222A SOT-23
12 Q307 Q309 6427002708 FET-P-CHNL NDS356AP SOT-23
Q301 Q302
13 Q308 Q311 6422007318 TR NPN MMBT3904 SOT-23
Q314 Q316
14 Q313 6423002308 TR PNP 2SA1037AK T146
15 Q315 6423000738 TR PNP MMBT3906 SOT-23
Recommended Spare Parts List Page 1
LITE-ON TECHNOLOGY CORP.
5 F, No. 16, Sec. 4, Nanking E. Road, Taipei, Taiwan
Tel:886-2-25706999 Fax: 886-2-25706888
URL:// www.liteontc.com.tw Printed in Taiwan