Set does not come on green light appears but goes out.

If a faint green lights come on, and then disappear almost immediately, then you usually have a bad Power supply board.
If instead unit stays in standby with green light on, then unit is in protect mode, because a wrong voltage had been detected, usually in consequence of a fault.
Try leaving power cord unplugged for one or two hours, even if it will not help in the first case.
If TV does not wake up, then the unit must be taken apart and tested to repair it.
Test on PSU is done visually checking PSU capacitors, reading voltages out on PSU contacts, and testing components. For safety reasons it must be done by a technician.
In case PSU is faulty, a replacement will be around $170:258762.
Here all parts for this TV.

Hi there,

Well it seems that there is some problem in the power unit of your TV, or may be some loosen shouldering or wire.....
you need to check for this, but first of all you can turn off your TV from main power and turn it on after 5 hours and see what's happen....

Let me know how old is your TV? 
Post comments if you need more help or information.....

Good Luck!!

Thanks