Hello XXXXXXXXXXXX:
Thank you for using just answer i ll be happy to assist you today,ok is there a light that is blinking in the front of the tv set if so how many times is it blinking,moreover do you have a power surge protector in between the tv set and the wall outlet and what have you tried if anything to correct this problem thank you.
Do you know how to soldering.
Ok click on the links below to get the service manual for your tv set model,this service manual will help you locate the relay inside of your tv set on the start up circuit, once you have found the relay solder the pins at the bottom on the pc board,try your tv set again and see if it works,if this suggestion does not work i would be thinking of replacing this relay because most likely it is faulty and causing this problem,hope this helps.
https://www.completeservicemanuals.com/index.php?ccUser=
http://www.servicemanuals.net/service.aspx
Thank You.
Technician
Electronics Technology Certified And Over 10 Years Of TV Repair.