SONY KDL26S2000 KDL32S2000 KDL46S2000 LED BLINKING CODES (2)

                                               [2]
                                                 STANDBY LED BLINKS 4 TIMES
     Four blinks occurs due to a failure of back light inverter board of a defective lamp.  Check whether there is 18.5V power to back light inverter board at CN6203 | CN6202 pins 9-12 on the G-1/G-2 board.  

• The 18.5V comes directly from the G-1/G-2 board  to the back light inverter board.  If the 18.5V is not present at CN6203/6202, the main power supply has failed.  Replace G-1/G-2 board.
• If the 18.5V is present, confirm that the main micro processor is sending "Back light-On" to the back light inverter board.  
• The voltage at CN7009/pin-2 on the BU board should measure 3.2V in normal operation.  If this 3.2V is not present then the Micro processor has failed.  Replace 'BU' board.
• If 3.2V is present at CN7009, check the 3.1V [Panel detect] coming from back light inverter board to the main micro processor.  The back light inverter pulls the 'Panel Detect' signal to '0V' when a failure occurs on the inverter board or lamp/s.  The 'Panel Detect' signal is measured at CN7009/pin-3.
• If the 3.1V is present, then the back light inverter board is functioning well, and attempting to communicate with the Main Micro-processor.  But, the main microprocessor is not processing the signal.  If this is the case, replace the 'BU' board.
• The presence of '0V' at CN7009/pin-3 indicates a back light inverter failure.  Use the following procedure to determine whether the back light inverter or the panel assembly is the defective component.

Caution:  Do NOT attempt to directly measure the inverter board output by place your VOM. 1000V or greater will be present at its output on initial Power On.

• To check the inverter board output, place the VOM probe on the top of the individual plastic lamp connectors.  Set the VOM to AC Volt range, place the prob on the top of the connector  directly above one of the two wires.  Each connector feed two lamps.  Place the vOM probe over each wire for proper measurements.  A good output will measure approximately [3VAC].  A bad will measure approximately about [1VAC] or less.  
• If any sigle output is bad, replace the back light inverter board. If all inverter board outputs are bad, check the [18V] supply from the main power supply before replacing the back light inverter board. 
• If [18V] is missing, check for loose or damaged connections between G-1/G-2 board and back light inverter board. 
• If 18V is present at the inverter board, and all outputs are bad, replace the inverter board.

                                                       Back light inverter board

                                                                      G-1 Board.

                                                                     G-2 board.

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