Sony KDL-40NX725 / KDL-46NX725 Service Manual ▷ View online
KDL-40NX725/46NX725
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SECTION 4 - TROUBLESHOOTING
PROTECTION SHUTDOWN
Self Diagnosis
Supported model
Critical voltages and circuit operations are monitored by the CPU
on the Main Board. If a fault is detected the Self-Diagnostic function
in the TV will force the TV to shut down by the CPU. The monitored
circuit in which the fault occurred will cause the CPU to flash the
standby LED in groups of repeating sequences. The number of
blinks in these groups identifies which voltage or circuit caused the
protection event.
Not all of the available protect codes are used in every model. For
Not all of the available protect codes are used in every model. For
example, models that are LED backlit do not use the 4-blink balancer
error as this circuit is found in models that are backlit with fluorescent
lamps. The information in this section contains the protect circuits and
diagnostics codes used in the models listed in this manual.
“Figure
4-3. Diagnostic Table” on page 34
provides guidance in locating the
possible component causing the shutdown.
STANDBY LED FLASH COUNT
Ambient Sensor/
(IR) Infrared Receiver
Picture Off /
Timer LED
Standby LED
Power LED
FIGURE 4-1. LED DISPLAY
2 times
5 times
LED ON 0.3 sec.
LED OFF 0.3 sec.
LED OFF 0.3 sec.
LED OFF
3 sec.
FIGURE 4-2. BLINK COUNT
KDL-40NX725/46NX725
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SECTION 4 - TROUBLESHOOTING
2X Blink - Main Power Error
A loss of REG12V from the power supply triggers this protect event.
A loss of REG12V from the power supply triggers this protect event.
The usual cause is a failure of the main switching supply. In some
instances, excessive loading on the secondary supply lines can
cause the switching regulator to stop, or fail again, if a replacement
board is installed.
3X Blink- DC Regulator/Audio Error
The Audio error can occur due on of the following error conditions.
3X Blink- DC Regulator/Audio Error
The Audio error can occur due on of the following error conditions.
● Defective DC Regulator on Main Board
● Defective Audio Amplifier (Main Board)
● Loss of AU12V (Open F4200 on Main Board)
● Loss of AU12V (Open Fuse on Power Supply Board)
In most cases, replacement of the main board will remedy a 3X error.
4X Blink – Balancer Error
The 4X error code is only used on models incorporating local
4X Blink – Balancer Error
The 4X error code is only used on models incorporating local
dimming LED backlighting. If a failure occurs on the LD board or one
of the LED’s fails in the panel the TV will shut down and display this
diagnostic code. Models using conventional non-local dimming LED
backlighting do not utilize this error code.
5X Blink - TCON Error
The 5X blink protection mode indicates a communications error
5X Blink - TCON Error
The 5X blink protection mode indicates a communications error
between the TCON Board and the X-Reality microprocessor on the
Main Board. If the TCON is available for replacement, replace the
TCON. If the TCON is not available, the LCD panel must be replaced
since the TCON circuit is part of the LCD panel assembly. In rare
cases a loose or defective LVDS cable could also be the cause.
6X Blink - Converter System Failure
If the converter circuit (located on the power supply board) fails to
If the converter circuit (located on the power supply board) fails to
start or shuts down due to an over-voltage or over-current condition,
the unit will shut down and generate a 6X error code. The diagnostic
page labels this as a “Backlight Failure” even though the backlights
are not a source of the problem.
7X Blink - Temperature Failure
These models do not display a temperature warning OSD dialogue
7X Blink - Temperature Failure
These models do not display a temperature warning OSD dialogue
box before shutting off and going into a 7X standby LED blink pattern.
The main objective when a 7X blink pattern occurs is to determine
which of the following possible defects is causing the excessive
temperature condition indication.
● Excessive Ambient Room Temperature
● Dust or Debris Blocking the TV Ventilation Apertures
● Defective Temperature Sensor or X-Reality Microprocessor
(Main Board)
The first step is to notice how long it takes the TV to shut off and
trigger a 7X blink protection mode.
If the TV has an actual excessive temperature condition it will
If the TV has an actual excessive temperature condition it will
take a considerable period of time to shut off and indicate a 7X
blink protection mode. This is because it will take time for the TV
components to heat up and for the temperature sensor to detect the
excessive temperature and shut the TV off.
KDL-40NX725/46NX725
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SECTION 4 - TROUBLESHOOTING
If the TV takes a considerable period of time to shut-off check the
following items:
● The TV should not be located too close to any heating
devices.
● The TV should have at least 4 inches of clearance around
the sides & rear, and 11 inches of clearance over the top to
ensure adequate ventilation.
● Check that all vented areas on the TV are clear of all dust
and debris.
● If the TV shuts off immediately after Power-On, replacement
of the main board is recommended.
KDL-40NX725/46NX725
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SECTION 4 - TROUBLESHOOTING
DIAGNOSTIC CODE DESCRIPTIONS
The Diagnostic Table provides an overview of the number of times the standby LED blinks and the possible location. To access the Triage
documents for the models listed in this manual, login into the Sony Authorized Servicer Portal at
http://www.sony.com/asp
.
Diagnostic Item
Diagnostic Item
Description
Number of times
Standby LED blinks
Probable Location
MAIN_POWER
Main Power Error
2
G4BW Board (40" Models Only)
G5AW Board (46" Models Only)
DC_ALERT
DC Regulator/Audio Error
AUD_PROT
Audio Error Detection
BALANCER
Balancer Error
4
LCD Panel
LD Board
TCON ERR
TCON Error
P_ID_ERR
Panel ID NVM Error
BACKLITE
Backlight Error
6
G4BW Board (40" Models Only)
G5AW Board (46" Models Only)
TEMP_ERR
Temperature Error
7
Ventilation
BATL Board
EMITTER
Emitter Error
10
HEM2 Board
3
BATL Board
5
TCON Control MT Board
FIGURE 4-3. DIAGNOSTIC TABLE
NOTE: To provide information to customers regarding how to use their TV features or FAQs, refer the customer to the i-MANUAL on their TV.
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