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26. Fan Control - KF-60DX100
Troubleshooting
If the backlight does not start and the TV shuts down with the Standby LED blinking four times, one or both of the
two fans has stopped. The suspected boards are: A board (fan regulators), G board (power supply) and M board
(fan control).
Procedure
1. At power ON, measure fan voltage from the power supply at CN1613/any pin = 11Vdc to the A board. No
voltage? Replace the A board.
2. At the A board or the fan connector (see the fan wire colors in Figure 26-2), measure the fan’s drive voltage
at CN1908/pin 6 and 9 (5Vdc and 9Vdc respectively) at power ON. If both voltages are present, the fans
should be rotating. Replace the fan if there is voltage but no rotation.
3. With the fan rotating, there should be 0Vdc at CN1908/pin 8 and 10. If either is 5Vdc, replace the corresponding
fan (see Figure 26-2). At this time, fan 1 is part of the light box (optical assembly) and not available separately.
4. There should be 0Vdc entering and leaving the A board going to the M board at CN1920/pin 23. This
connector is accessible from under the bottom A board. Tilt the TV board assembly package up and locate
the connector under the M board. If this A board output voltage is 5Vdc (not the same as input), replace the
A board. If CN1920/pin 23 is 0Vdc, replace the M board.