[3]
STANDBY LED BLINKS 5 TIMES
Overall Power supply Protection:
The purpose of this protection mode is to indicate a failure on Main Power Supply [IC6100] on the G-1/G-2 board. The primary monitor voltage is 18V. If the Main Power Supply does not start or remain running the 18V will not be developed and the Main Micro processor will detect an overall poser supply failure.
STANDBY LED BLINKS 5 TIMES
Overall Power supply Protection:
The purpose of this protection mode is to indicate a failure on Main Power Supply [IC6100] on the G-1/G-2 board. The primary monitor voltage is 18V. If the Main Power Supply does not start or remain running the 18V will not be developed and the Main Micro processor will detect an overall poser supply failure.
- The above said 18V is applied to a voltage divider consisting of R1031, R1034 & R1037. The voltage across R1037 [3.1V] which is stabilized and delayed by C1007 and applied to main microprocessor IC1001/pin-82. The presence of this 3.1V indicates a properly functioning main power supply. If the 18V is not developed for any reason, the this 3.1V will not be present and the Main Multiprocessing will detect a power supply failure and will indicate it by 5 blinks of standby light before shut down.
Main reasons:
- Failure of main converter IC6100
- Loss of 3.3V Power-On signal from Main Microprocessor IC1001/pin-32.
- Excessive 19V supply to the PFC circuit.
- Failure of Inrush Relay.
- 18.5V over voltage condition.
Main Power Supply Converter IC6100
- Confirm that both 3.3V Power-On signal and the 18.5V increase, and stabilize to their respective levels before protection mode shut-down.
- The presence of 3.3V indicates that the converter IC6100 is most likely getting the necessary VCC input, and the presence of 18.5V that the converter IC is starting and developing the secondary voltages. Therefore, some other fault is shutting down the TV. It is rare case that IC6100 fail. This IC [MCZ3000D] integrated circuit has been very reliable.
Loss of 3.3V Power-On signal from the Main Microprocessor.
- The Power-On signal is generate by Main Microprocessor IC1001/ pin-32 on the 'BU' board. The tricky part about troubleshooting this failure is determining if the main microprocessor is failing to generate the Power-On signal if one of the two latch circuits [Q6202/Q6204 & Q6105/Q6107] on the G-1/G-2 board is pulling the Power-On signal low. There is two latch circuits located on the G-1/G-2 board. These latch circuits connect directly to Power-On signal line.
- If the Power-On signal shows no signs of increasing towards 3.3V, the the failure should be with the Main Microprocessor. Before replacing the 'BU' board, check all the connections between G-1/G-2 to BU board.
- If the Power-On signal increases to 3.3V, and then goes back to '0V' one of the latch circuit are being activated.
The power-On signal can also be checked unloaded. Disconnect [CN6202/CN6203] from G-1/G-2 board and check if 3.3V is present. If it is there, indicates that Latch circuits are activating due ot a failure of G1/G2 board, and pulling the Power-On line Low.
- Check for excessive 19V supply to the PFC circuit.
- InRush relay.
- 18.5V over-voltage condition.
Contd:
