Sony KDL-40HX750 / KDL-46HX750 / KDL-55HX750 Service Manual ▷ View online
KDL-40/46/55HX750(CH)
5
WARNINGS AND CAUTIONS
USE CAUTION WHEN HANDLING THE LCD PANEL
When repairing the LCD panel, be sure you are grounded by using a wrist band.
When repairing the LCD panel on the wall, the LCD panel must be secured using the 4 mounting holes on the rear cover.
When repairing the LCD panel on the wall, the LCD panel must be secured using the 4 mounting holes on the rear cover.
1)
Do not press on the panel or frame edge to avoid the risk of electric shock.
2)
Do not scratch or press on the panel with any sharp objects.
3)
Do not leave the module in high temperatures or in areas of high humidity for an extended period of time.
4)
Do not expose the LCD panel to direct sunlight.
5)
Avoid contact with water. It may cause a short circuit within the module.
6)
Disconnect the AC power when replacing the backlight (CCFL) or inverter circuit. (High voltage occurs at the inverter circuit at 650Vrms.)
7)
Always clean the LCD panel with a soft cloth material.
8)
Use care when handling the wires or connectors of the inverter circuit. Damaging the wires may cause a short.
9)
Protect the panel from ESD to avoid damaging the electronic circuit (C-MOS).
10) It is recommended not to exceed 1 hour of Power-On nor Burn-in period with LCD panel face down condition, in repair activity.
KDL-40/46/55HX750(CH)
6
SAFETY CHECK-OUT
After correcting the original service problem, perform the following safety checks before releasing the set to the customer:
1. Check the area of your repair for unsoldered or poorly soldered connections. Check the entire board surface for solder splashes and bridges.
2. Check the interboard wiring to ensure that no wires are “pinched” or touching high-wattage resistors.
3. Check that all control knobs, shields, covers, ground straps, and mounting hardware have been replaced. Be absolutely certain that you have replaced all the insulators.
4. Look for unauthorized replacement parts, particularly transistors, that were installed during a previous repair. Point them out to the customer and recommend their replacement.
5. Look for parts which, though functioning, show obvious signs of deterioration. Point them out to the customer and recommend their replacement.
6. Check the line cords for cracks and abrasion. Recommend the replacement of any such line cord to the customer.
7. Check the antenna terminals, metal trim, “metallized” knobs, screws, and all other exposed metal parts for AC leakage. Check leakage as described below.
8. For safety reasons, repairing the Power board and/or Inverter board is prohibited.
KDL-40/46/55HX750(CH)
7
SAFETY CHECK-OUT
Leakage Test
The AC leakage from any exposed metal part to earth ground and from all exposed metal parts to any exposed
metal part having a return to chassis, must not exceed 0.5 mA (500 microamperes).
Leakage current can be measured by any one of three methods.
The AC leakage from any exposed metal part to earth ground and from all exposed metal parts to any exposed
metal part having a return to chassis, must not exceed 0.5 mA (500 microamperes).
Leakage current can be measured by any one of three methods.
1. A commercial leakage tester, such as the Simpson 229 or RCA WT-540A. Follow the manufacturers’
instructions to use these instructions.
2. A battery-operated AC milliampmeter. The Data Precision 245 digital multimeter is suitable for this job.
3. Measuring the voltage drop across a resistor by means of a VOM or battery-operated AC voltmeter. The
3. Measuring the voltage drop across a resistor by means of a VOM or battery-operated AC voltmeter. The
“limit” indication is 0.75 V, so analog meters must have an accurate low voltage scale.
The Simpson’s 250 and Sanwa SH-63TRD are examples of passive VOMs that are suitable. Nearly all
battery-operated digital multimeters that have a 2 VAC range are suitable (see Figure A).
The Simpson’s 250 and Sanwa SH-63TRD are examples of passive VOMs that are suitable. Nearly all
battery-operated digital multimeters that have a 2 VAC range are suitable (see Figure A).
How to Find a Good Earth Ground
A cold-water pipe is a guaranteed earth ground; the cover-plate retaining screw on most AC outlet boxes is also
at earth ground.
If the retaining screw is to be used as your earth ground, verify that it is at ground by measuring the resistance
between it and a cold-water pipe with an ohmmeter. The reading should be zero ohms.
If a cold-water pipe is not accessible, connect a 60- to 100-watt trouble- light (not a neon lamp) between the hot
side of the receptacle and the retaining screw. Try both slots, if necessary, to locate the hot side on the line; the
lamp should light at normal brilliance if the screw is at ground potential (see Figure B).
A cold-water pipe is a guaranteed earth ground; the cover-plate retaining screw on most AC outlet boxes is also
at earth ground.
If the retaining screw is to be used as your earth ground, verify that it is at ground by measuring the resistance
between it and a cold-water pipe with an ohmmeter. The reading should be zero ohms.
If a cold-water pipe is not accessible, connect a 60- to 100-watt trouble- light (not a neon lamp) between the hot
side of the receptacle and the retaining screw. Try both slots, if necessary, to locate the hot side on the line; the
lamp should light at normal brilliance if the screw is at ground potential (see Figure B).
KDL-40/46/55HX750(CH)
8
SELF DIAGNOSIS FUNCTION
DIAGNOSTIC TEST INDICATORS
When an error occurs, the STANDBY LED will flash a set number of times to
indicate the possible cause of the problem.
If there is more than one error, the LED will identify the first of the problem areas.
Result for all of the following diagnostic items are displayed on screen.
If the screen displays a “0”, no error has occurred .
When an error occurs, the STANDBY LED will flash a set number of times to
indicate the possible cause of the problem.
If there is more than one error, the LED will identify the first of the problem areas.
Result for all of the following diagnostic items are displayed on screen.
If the screen displays a “0”, no error has occurred .
The units in this manual contain a self-diagnostic function. If an error occurs, the STANDBY LED will automatically begin to flash.
The number of times the LED flashes translates to a probable source of the problem.
A definition of the STANDBY LED flash indicators is listed in the instruction manual for the user’s knowledge and reference.
If an error symptom cannot be reproduced, the remote commander can be used to review the failure occurrence data stored in memory to reveal past problems and how often these
problems occur.
The number of times the LED flashes translates to a probable source of the problem.
A definition of the STANDBY LED flash indicators is listed in the instruction manual for the user’s knowledge and reference.
If an error symptom cannot be reproduced, the remote commander can be used to review the failure occurrence data stored in memory to reveal past problems and how often these
problems occur.
0.5
0.5
3
DISPLAY OF STANDBY LED FLASH COUNT
SELF-DIAGNOSTIC SCREEN DISPLAY
For errors with symptoms such as “power sometimes shuts off” or “screen sometimes goes out” that cannot be confirmed, it is possible to bring up past occurrences of failure for
confirmation on the screen:
For errors with symptoms such as “power sometimes shuts off” or “screen sometimes goes out” that cannot be confirmed, it is possible to bring up past occurrences of failure for
confirmation on the screen:
[To Bring Up Screen Test]
In standby mode, press buttons on the remote commander sequentially in rapid succession as shown below:
In standby mode, press buttons on the remote commander sequentially in rapid succession as shown below:
5
*
: Note that this differs from entering the service mode (volume +)
*
DISPLAY
TV POWER
Channel
Volume
STBY LED
Flash time
Service menu Item
name
(Screeen Display)
Diagnostic Item Description
2
MAIN_POWE
Main Power Over Voltage Protection
DC_ALERT
DC_ALERT
AUD_PROT
Audio Abnorm al Detection
HDMI_EQ
HDMI equalizer/s witch I2C NACK
TU_DEMOD
Tuner or dem odulator I2C NACK
4
-
Not us ed
HFR_ERR
HFR Error
TCON_ERR
T-CON Error
P_ID_ERR
Panel ID NVM Error
6
BACKLITE
LED driver protection
TEMP_ERR
Therm al Error
FAN_ERR
Not us ed
8
-
Software Error (Also the m ain board’s m em ory or Wi-Fi
m odule is a sus pect)
m odule is a sus pect)
9
-
Not us ed
10
EMIT_ERR
Trans m itter board not connected
11
-
Not us ed
12
-
Not us ed
3
5
7
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