A few green flashes and the TV shuts down, blinking stand by light.

The red power light flashes at 3sec intervals indicating that the light and/or the outer panel door are not secured.

Hi,
KP-51HW40 shuts off due to incorrect white balance and blue arch lines is an evidence of that incorrect white balance. I hope tv standby red light would flashing 5 times then 3 seconds pause and again 5 times when tv shuts down.
This is rear projection tv that has three picture tubes (red-green-blue) inside to generate picture that projected at front screen. These three picture tubes must be drive with correct drive voltage to produce good picture of each color.
Solution for your tv problem is Screen Voltage adjustment that can be done easily if you are handy with electronics stuff repair.
Let me know your expertise level to guide you more and if you feel unconformable by tv repair then local tv repairman will help you to adjust white balance in tv.
Hope these info will help you.
Let me know if you have additional questions.
Thanks.

Probable Lamp. If lamp hasn't bown the red Lamp Lite won't flash but other lamp issues cause stby timer light to continue flashing. If stby red lite is flashing, count the no. of times flashing - could open thermal fuse (6X flashing)

Funai used lousy wire going from the inverter board to the backlight tubes. Look for any wires that are touching each other. The insulation could have broke down between them and started arching. Get some heatshrink tubing to recover the damaged wires.

I have seen this flashing before, this could be an indication that the picture tube is weak, what happens is that if the white balance is off there is a circuit called akb it monitors the kathode of each gun and if they are not in balance it will attempt to balance it out. if it can't the picture will begin to flash, sometimes in some models the power light will blink 5 times. On some models the power light will only flash if the tv gives up trying to compinsate for white balance and shuts off compeletely. If you see the tv shutting off with 5 blinks then you know for sure it is time for a new set.

you need a new Blue CRT you can get them at the following link.
http://servicemanuals.vstore.ca/

Yup, it seems a lamp problem can give a blinking green light over the 10 times (1 - 10 times for diagnostic codes), but in my case rather than replace the bulb if it works for a minute then resets with the green light blinking, do what I did.
Take the lamp out and inspect it, it has breather screens top and bottom, if it cant breath because there clogged with dust, clean them, and you can remove the screens, use q-tips and clean the inside. I saved the cost of a lamp and it's working fine!

I had the same problem. i was told by one of these so-called experts @ fixya that my flyback transformer needed to be replaced (the 8 blinks on the standby was the indicator). but i recently replaced it and im having the same problem. sorry. no advice. good luck.

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)

If you see a neon light in the crt board and it lights up is because the green picture tube is arking inside,the light is supposed to do that and is why is there,the only way to correct the problem is by replacing the picture tube and it can be costly sometimes,there is another way but this will not take care of the problem for good,it might go away for a while but it might return,is hard to tell if it might work,what you need to do is lift the set from the ground about 3 inches and drop it,sometimes just by doing it once it works ,other times it takes more than once,do not over do it or something else might break,is an option you dont have to take and you still have the option to replace the tube.Let Us know how it goes or if you need more information.