SONY KDL-26S2000 - KDL-32S2000 - KDL-40S2000 - KDL-46S2000
TROUBLESHOOTING TIPS
Troubleshooting
Tips
10.5V & Panel 5V Low-Voltage Protection (1X)
Reference Figures 3-1, 3-2, and 2-1 The first step is to check that the Main Power Supply is developing 10.5V at CN6200/CN6202/pins 7 & 8. The voltage should increase to 10.5V and stabilize. If 10.5V in not present then the Main Power is defective, in this case, replace the G1/G2-Board. If the 10.5V is present the next step is to determine if the Panel 5V is being developed by the switching regulator (IC7000) on the BU-Board. Check the voltage at TP1 (Panel 5V) on the BU-Board, this is the 5V output of IC7000. If the Panels 15V does approach 15V before the TV shuts down, then the regulator has failed. In this case, replace the BU-Board. If both the 10.5V and Panel 5V are OK then the protection circuit (Q7500 & Q7502) itself may have failed. If 3.1V is present at CN1001/pin 154 then the protection circuit is working properly and the Main Microprocessor is not processing the signal correctly. If 0V is present at CN1001/pin 154, then the protection circuit has failed. In either case, you would replace the BU-Board.
D5V Under-Voltage Protection (2X)
There are only two failures that can cause a 2X protection mode, they are as follows.
#Open PS7000
# Defective 5V (D5V) regulator IC7005
Both components are located on the BU-Board, and therefore would warrant are BU-Board replacement. However, for a possible quick and easy fix check for an open PS7000. Replace if open. If PS7000 is OK, then the output of the 5V regulator IC7005 should be check to confirm a BU-Board failure. If the 5V is missing, then replace the BU-Board.
10.5V & Panel 5V Low-Voltage Protection (1X)
Reference Figures 3-1, 3-2, and 2-1 The first step is to check that the Main Power Supply is developing 10.5V at CN6200/CN6202/pins 7 & 8. The voltage should increase to 10.5V and stabilize. If 10.5V in not present then the Main Power is defective, in this case, replace the G1/G2-Board. If the 10.5V is present the next step is to determine if the Panel 5V is being developed by the switching regulator (IC7000) on the BU-Board. Check the voltage at TP1 (Panel 5V) on the BU-Board, this is the 5V output of IC7000. If the Panels 15V does approach 15V before the TV shuts down, then the regulator has failed. In this case, replace the BU-Board. If both the 10.5V and Panel 5V are OK then the protection circuit (Q7500 & Q7502) itself may have failed. If 3.1V is present at CN1001/pin 154 then the protection circuit is working properly and the Main Microprocessor is not processing the signal correctly. If 0V is present at CN1001/pin 154, then the protection circuit has failed. In either case, you would replace the BU-Board.
D5V Under-Voltage Protection (2X)
There are only two failures that can cause a 2X protection mode, they are as follows.
#Open PS7000
# Defective 5V (D5V) regulator IC7005
Both components are located on the BU-Board, and therefore would warrant are BU-Board replacement. However, for a possible quick and easy fix check for an open PS7000. Replace if open. If PS7000 is OK, then the output of the 5V regulator IC7005 should be check to confirm a BU-Board failure. If the 5V is missing, then replace the BU-Board.
3.3V & 1.8V Low-Voltage
Protection (3X)
There are four failures that will cause a 3X protection mode state (all located on the BU-Board), and they are as follows.
# Open F7000
# Defective 3.3V Regulator IC7001 (TP3)
# Defective 1.8V Regulator IC7002 (TP2)
# Defective 2.4V Regulator IC7004 (TP4)
If 0V is present at any of the regulator output test points or if F7000 is open, then replace the defective component or the BU-Board. If F7000 and all voltages (3.3V, 2.4V, and 1.8V) at the test points check OK and the TV still shuts down (3X), then a component in the protection circuit (Q7504, Q7505, Q7506, Q7503, D7508, D7509, and D7510) itself may have failed.
Check for the presence of 3.1V at IC1001/pin 163. If 3.1V is present at CN1001/pin163, then the regulators and protection circuits are working properly. The failure is most likely the Main Microprocessor; it is not processing the DC ALERT 1 signal properly. Replace the BU-Board.
Backlight Protection (4X)
The 4X protection occurs due to a failure of the Backlight-Inverter board (failure to drive the Cold Cathode Fluorescent Lamps), or a defective Lamp. Therefore, you will first check the 18.5V power supply for the BacklightInverter board at CN6203/CN6202/pins 9-12 on the G1/G2-Board. The 18.5V comes directly from the G1/G2-Board to the Backlight-Inverter board. Therefore, if the 18.5V is not present at CN6202/CN6203 then the Main Power Supply has failed. Replace the G1/G2-Board. If the 18.5V is present at CN6202/CN6203, then the next step is to confirm that the Main Microprocessor is sending the “Backlight-ON” to the Backlight-Inverter board.
The voltage at CN7009/pin 2 on the BU-Board should measure 3.2V in normal operation. If the 3.2V is not present then the Main Microprocessor has failed. Replace the BU-Board.
If the 3.2V is present at CN7009, then the next step is to check the 3.1V “Panel Detect” coming from the Backlight-Inverter board to the Main Microprocessor. The Backlight-Inverter pulls the “Panel Detect” signal to 0V when a failure occurs on the Inverter Board or if a Lamp fails. The “Panel Detect” signal is measured at CN7009/pin 3.
If the voltage is 3.1V, then the Backlight-Inverter is working properly, and attempting to communicate with the Main Microprocessor. However, the Main Microprocessor is not processing the signal. In this case, replace the BU-Board.
The presence of 0V at CN7009/pin 3 indicates a Backlight-Inverter failure. Use the following procedure to determine whether the Backlight Inverter or the Panel Assembly is the defective component.
Caution: Do not attempt to directly measure the Backlight Inverter Board output directly. 1000V or greater is present at the outout on initail power ON.
The best way to check the Inverter Board output is to place your VOM probe on top of the individual plastic lamp connectors. Set the VOM to AC volts, place the probe on top of the connector directly above one of the two wires (each connector feeds two lamps).
Place the VOM probe over each wire for proper measurements. A good output will measure approximately 3VAC. A bad output will measure aproxiamatey 1VAC or less. If any single output is bad replace the Backlight Inverter Board. If all Inverter Board outputs are bad, check the 18V supply voltage from the Main Power supply before replacing the Backlight Inverter Board. If the 18V is missing check for loose or damaged connections between the G1/G2-Board and the Backlight Inverter Board. If the 18V is present at the Inverter Board, however, all output are bad then replace the Backlight Inverter Board.
There are four failures that will cause a 3X protection mode state (all located on the BU-Board), and they are as follows.
# Open F7000
# Defective 3.3V Regulator IC7001 (TP3)
# Defective 1.8V Regulator IC7002 (TP2)
# Defective 2.4V Regulator IC7004 (TP4)
If 0V is present at any of the regulator output test points or if F7000 is open, then replace the defective component or the BU-Board. If F7000 and all voltages (3.3V, 2.4V, and 1.8V) at the test points check OK and the TV still shuts down (3X), then a component in the protection circuit (Q7504, Q7505, Q7506, Q7503, D7508, D7509, and D7510) itself may have failed.
Check for the presence of 3.1V at IC1001/pin 163. If 3.1V is present at CN1001/pin163, then the regulators and protection circuits are working properly. The failure is most likely the Main Microprocessor; it is not processing the DC ALERT 1 signal properly. Replace the BU-Board.
Backlight Protection (4X)
The 4X protection occurs due to a failure of the Backlight-Inverter board (failure to drive the Cold Cathode Fluorescent Lamps), or a defective Lamp. Therefore, you will first check the 18.5V power supply for the BacklightInverter board at CN6203/CN6202/pins 9-12 on the G1/G2-Board. The 18.5V comes directly from the G1/G2-Board to the Backlight-Inverter board. Therefore, if the 18.5V is not present at CN6202/CN6203 then the Main Power Supply has failed. Replace the G1/G2-Board. If the 18.5V is present at CN6202/CN6203, then the next step is to confirm that the Main Microprocessor is sending the “Backlight-ON” to the Backlight-Inverter board.
The voltage at CN7009/pin 2 on the BU-Board should measure 3.2V in normal operation. If the 3.2V is not present then the Main Microprocessor has failed. Replace the BU-Board.
If the 3.2V is present at CN7009, then the next step is to check the 3.1V “Panel Detect” coming from the Backlight-Inverter board to the Main Microprocessor. The Backlight-Inverter pulls the “Panel Detect” signal to 0V when a failure occurs on the Inverter Board or if a Lamp fails. The “Panel Detect” signal is measured at CN7009/pin 3.
If the voltage is 3.1V, then the Backlight-Inverter is working properly, and attempting to communicate with the Main Microprocessor. However, the Main Microprocessor is not processing the signal. In this case, replace the BU-Board.
The presence of 0V at CN7009/pin 3 indicates a Backlight-Inverter failure. Use the following procedure to determine whether the Backlight Inverter or the Panel Assembly is the defective component.
Caution: Do not attempt to directly measure the Backlight Inverter Board output directly. 1000V or greater is present at the outout on initail power ON.
The best way to check the Inverter Board output is to place your VOM probe on top of the individual plastic lamp connectors. Set the VOM to AC volts, place the probe on top of the connector directly above one of the two wires (each connector feeds two lamps).
Place the VOM probe over each wire for proper measurements. A good output will measure approximately 3VAC. A bad output will measure aproxiamatey 1VAC or less. If any single output is bad replace the Backlight Inverter Board. If all Inverter Board outputs are bad, check the 18V supply voltage from the Main Power supply before replacing the Backlight Inverter Board. If the 18V is missing check for loose or damaged connections between the G1/G2-Board and the Backlight Inverter Board. If the 18V is present at the Inverter Board, however, all output are bad then replace the Backlight Inverter Board.
Overall Power Supply Protection (5X)
You will start troubleshooting a 5X protection mode by listening for an InRush relay click when the TV is turned ON. The presence or absence of the relay click is very helpful in determining had to proceed in troubleshooting a 5X protection mode. Let us first follow the “No” answer for the “Is Relay Click Heard?” question diamond. If no click is heard when the TV is turned ON, then check for the presence on the “Relay-ON” (or Power 5) voltage at CN6202/CN6203/pin 4. This voltage (comes from the Main Microprocessor IC1001/pin 20, and is using solely to turn On the InRush relay.
If the 3.3V is present at CN6203/CN6202, then the Main Microprocessor is working properly and the failure exists on the G1/G2-Board. Replace the G1/G2-Board. If the 3.3V is missing, then the Main Microprocessor is not sending the voltage. In this case, either Main Microprocessor has failure, or there is an open circuit between the Main Microprocessor and CN6203/CN6202. In either case, replace the BU-Board.
Let us now go back to the first question diamond and follow the “Yes” answer path. If the relay click is heard when the TV is turned ON, then check for the presence of the 18.5V at CN6202/CN6203/pin 13. The 18.5V will first be checked for an excessive voltage (or OVP) condition. If the 18.5V exceeds 22V the latch (Q6202 & Q6204) will activate and pull the Power-ON line low, and shut OFF the main power supply. In this case, replace the G1/G2-Board. However, if the 18.5V is present and stable at the proper level, then the Main Microprocessor is not processing the voltage at IC1001/pin 82. Therefore, replace the BU-Board. If the 18.5V is not present, then the next step is to check if the Power-ON voltage (3.3V) is present at CN6202/CN6203/pin 2. This voltage is used to turn on the Main Power Supply IC6100. If the 3.3V is present then the problem exists on the G1/G2-Board. If the 3.3V is missing then the problem exists on the BU-Board
You will start troubleshooting a 5X protection mode by listening for an InRush relay click when the TV is turned ON. The presence or absence of the relay click is very helpful in determining had to proceed in troubleshooting a 5X protection mode. Let us first follow the “No” answer for the “Is Relay Click Heard?” question diamond. If no click is heard when the TV is turned ON, then check for the presence on the “Relay-ON” (or Power 5) voltage at CN6202/CN6203/pin 4. This voltage (comes from the Main Microprocessor IC1001/pin 20, and is using solely to turn On the InRush relay.
If the 3.3V is present at CN6203/CN6202, then the Main Microprocessor is working properly and the failure exists on the G1/G2-Board. Replace the G1/G2-Board. If the 3.3V is missing, then the Main Microprocessor is not sending the voltage. In this case, either Main Microprocessor has failure, or there is an open circuit between the Main Microprocessor and CN6203/CN6202. In either case, replace the BU-Board.
Let us now go back to the first question diamond and follow the “Yes” answer path. If the relay click is heard when the TV is turned ON, then check for the presence of the 18.5V at CN6202/CN6203/pin 13. The 18.5V will first be checked for an excessive voltage (or OVP) condition. If the 18.5V exceeds 22V the latch (Q6202 & Q6204) will activate and pull the Power-ON line low, and shut OFF the main power supply. In this case, replace the G1/G2-Board. However, if the 18.5V is present and stable at the proper level, then the Main Microprocessor is not processing the voltage at IC1001/pin 82. Therefore, replace the BU-Board. If the 18.5V is not present, then the next step is to check if the Power-ON voltage (3.3V) is present at CN6202/CN6203/pin 2. This voltage is used to turn on the Main Power Supply IC6100. If the 3.3V is present then the problem exists on the G1/G2-Board. If the 3.3V is missing then the problem exists on the BU-Board
Audio Output Error (6X)
There are three possible failures that can cause a 6X protection mode, and they are as follows.
# Short Audio Amplifier Outputs
# Lose of 15V Supply
# Lose of 9V Supply
The key to determining what to check first is if audio is heard before the TV shuts OFF.
If audio is heard before the TV shuts OFF, then the next step is to check the 15V supply at CN7503/pin 1. If the voltage is missing replace the G1/G2-Board. If the voltage is present, first check the fuse PS7001 for a possible easy fix. If the fuse is OK replace the AU-Board. If no audio is heard before the TV shuts OFF check for 9V at CN9502/pin 1. If the 9V is missing replace the BU-Board. However, if the 9V is present check and confirm that the protection circuit output voltage is making it to the Main Microprocessor IC1001/pin 26. If 2.8V is present at IC1001/pin 26 then the Main Microprocessor is defective. Replace the BU-Board. If the voltage at IC1001/pin 26 is 0V then the audio output circuit has actually failed. In this case, replace the AU-Board. A shorted audio output or a DC voltage level measure across the audio output will cause a 6X protection mode indication. In either case the problem will exist in the audio circuitry on the AU-Board.
There are three possible failures that can cause a 6X protection mode, and they are as follows.
# Short Audio Amplifier Outputs
# Lose of 15V Supply
# Lose of 9V Supply
The key to determining what to check first is if audio is heard before the TV shuts OFF.
If audio is heard before the TV shuts OFF, then the next step is to check the 15V supply at CN7503/pin 1. If the voltage is missing replace the G1/G2-Board. If the voltage is present, first check the fuse PS7001 for a possible easy fix. If the fuse is OK replace the AU-Board. If no audio is heard before the TV shuts OFF check for 9V at CN9502/pin 1. If the 9V is missing replace the BU-Board. However, if the 9V is present check and confirm that the protection circuit output voltage is making it to the Main Microprocessor IC1001/pin 26. If 2.8V is present at IC1001/pin 26 then the Main Microprocessor is defective. Replace the BU-Board. If the voltage at IC1001/pin 26 is 0V then the audio output circuit has actually failed. In this case, replace the AU-Board. A shorted audio output or a DC voltage level measure across the audio output will cause a 6X protection mode indication. In either case the problem will exist in the audio circuitry on the AU-Board.
Internal Temperature Protection (7X)
The primary symptom to note when a 7X (Temperature) protection mode is occurring is, how quickly the TV shuts OFF and goes into the protection mode. Does the TV shutdown immediately after the power button is press, or does the TV operate OK for a short period of time and then shutdown?
A true temperature problem where the internal temperature is excessive will take some time to detect. The temperature itself will take time to increase and the temperature sensor will take time to sense the temperature and communicate the information to the Main Microprocessor. Therefore, if the TV immediately shuts down then the protection sensor IC1007 has most likely failed, causing the 7X protection mode. Replace the B-Board. If it does take some period for the TV to shutdown and produce a 7X protection mode indication, then further steps must be taken to resolve the problem. First, check the TV ventilation, room temperature, and TV mounting area.
In most cases, cleaning the TV vents, adjusting the room temperature, and/or remounting the TV will solve the temperature problem. Also, confirm that the TV is not mounted too close to home heating elements (e.g. radiators).
If the previous maintenance steps do not resolve the temperature problem, then an internal component may be causing the excessive temperature. Although this is an extremely rare occurrence you can check the G1/G2- Board and LCD Panel Assembly for excessive heat.
TRIDENT (Scan Converter) Protection (8X)
There are no other components within the TV that can cause an 8X protection mode indication. The 8X protection mode indicates a TRIDENT video processor internal failure, specifically the failure of the Scan Converter section. If the 8X indication occurs, replace the BU-Board to repair the failure.
The primary symptom to note when a 7X (Temperature) protection mode is occurring is, how quickly the TV shuts OFF and goes into the protection mode. Does the TV shutdown immediately after the power button is press, or does the TV operate OK for a short period of time and then shutdown?
A true temperature problem where the internal temperature is excessive will take some time to detect. The temperature itself will take time to increase and the temperature sensor will take time to sense the temperature and communicate the information to the Main Microprocessor. Therefore, if the TV immediately shuts down then the protection sensor IC1007 has most likely failed, causing the 7X protection mode. Replace the B-Board. If it does take some period for the TV to shutdown and produce a 7X protection mode indication, then further steps must be taken to resolve the problem. First, check the TV ventilation, room temperature, and TV mounting area.
In most cases, cleaning the TV vents, adjusting the room temperature, and/or remounting the TV will solve the temperature problem. Also, confirm that the TV is not mounted too close to home heating elements (e.g. radiators).
If the previous maintenance steps do not resolve the temperature problem, then an internal component may be causing the excessive temperature. Although this is an extremely rare occurrence you can check the G1/G2- Board and LCD Panel Assembly for excessive heat.
TRIDENT (Scan Converter) Protection (8X)
There are no other components within the TV that can cause an 8X protection mode indication. The 8X protection mode indicates a TRIDENT video processor internal failure, specifically the failure of the Scan Converter section. If the 8X indication occurs, replace the BU-Board to repair the failure.
