The constant blinking green light means that the TV is not booting up. This is a common problem on this set.You need to remove the shield from the DM board (standing upright on the left where the DTV RF connector is)and inside you will see the four leaky capacitors (1000 MFD 16 VOLT)replace them,plug the TV in and wait 70 seconds for the blinking light to stop,then turn on the TV.The hard part will be removing the board from the TV(lots of screws and connectors,takes time)
You must do some checks first:LED does not stop blinking after plug in. Verify the standby supplies, 12-volts at connector KA pin 17, 6-volts at KA pin 18 and the 28-volts at KA pin 19, if the supplies are present suspect the DM PCB part # 934C067001 LED does not stop blinking after plug in. Check C9B01, C9B02, C9B10, and C9B11 (1000 UFD 16) on the DM PCB, if they are bad replace them with part # 181P734030 (680 UFD 16 V). LED stops blinking after 70 seconds of plug in but will not power on. This model is equipped with a keyboard lock feature; this can be mistaken as a no power condition. To unlock the keyboard press and hold the "menu" button on the front panel for 10 seconds . LED stops blinking after 70 seconds of plug in but will not power on. Check for 3.2 volts DC at connector RF pin 4 and 5 on the Signal PCB if low suspect problems with the switches/buttons on the Control PCB part # 935D736001. LED stops blinking after 70 seconds of plug in but will not power on. Keyboard is not locked and key inputs at connector RF pin 4 and 5 check good suspect the E2P PCB part # 934C061001.
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Hope it may help you ;