Sony KDL-32EX725 Service Manual page 37

2X Blink - Main Power Error
A 2X protection mode blink pattern can be activated due one of the
following defects.
● Loss of REG12V (LVP)*
● Loss of -125V (Single Line)
● Excessive -125V Level (OVP)*
● Loss of Power-ON Signal
● Excessive PFC Voltage (OVP)
● Excessive PFC Temperature (OTP)
*Low Voltage Protection (LVP)
*Over Voltage Protection (OVP)
A loss or excessive condition of the REG12VDC secondary voltage
from the main power supply IC6351 will cause a 2X blink pattern on
the standby LED. The 12Vdc can be checked at CN6704/pin 16.
If the measurement is 0V or rises above 12Vdc (approaches 15V)
before the TV shuts down the Power Supply Board is defective.
If approximately 12Vdc is present and remains below 12Vdc before
shutdown then further troubleshooting is necessary to determine the
defective component.
After confirming proper REG12V levels, check the Negative LED
Backlight supply levels. A loss or excessive condition of the negative
supply will cause a 2X blink failure. The voltage level can be checked
at CN6701/pins 1 & 3 before the TV shuts off. There will be 2 to 4
wires (Red & Blue) depending on the panel size. All individual wires
should be checked for proper voltage level. In normal operation the
voltage level will initially rise to approximately -175V and then should
KDL-32EX725/40EX725/55EX725
SECTION 4 - TROUBLESHOOTING
regulate down to between 89V and 125V depending on the Backlight
adjustment in the User Menu. If one of the negative supplies is 0V
or rises above -175V before shut-off then the Power Supply Board is
defective, replace it to fix the problem.
A defective X-Reality processor on the Main Board or Switch circuit
on the Power Supply Board will cause a loss of the Power-ON signal
(2X). To determine which component is defective check the Power-
ON voltage level at CN6704/pin 1. In normal operation 3V should be
measured. If the 3V is present before shut-off then the Power Supply
Board is defective. If 0V is measured before shut-off then the Main
Board is defective.
Finally, there are PFC protection circuits on the Power Supply Board
that when activated will cause a 2X blink protection mode. The PFC
circuit is monitored for both over-voltage and over-temperature.
Therefore, if all the previously discussed circuits checkout okay,
there could still be a problem on the Power Supply Board in the PFC
circuit causing the 2X blink. Replacing the Power Supply Board will
fix the TV.
3X Blink- DC Regulator/Audio Error
The Audio error can occur due on of the following error conditions.
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●
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●
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Defective DC Regulator on Main Board
Shorted or Damaged Speaker Connections
Defective Audio Amplifier (Main Board)
Loss of AU12V (Open F4200 on Main Board)
Loss of AU12V (Open Fuse on Power Supply Board)
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