Hello, Welcome to Justanswer. My name is XXXXX XXXXX I will be glad to help you out.
I do not have very good news for you but one thing that this is a common problem and can be fixed.
Basically you have a power supply issue.
The problem you are facing is a common problem which usually occurs as the TV gets older. It is a power supply issue. The power supply board has many tiny components like capacitors and resistors whose values change over the course of time and due to different operating conditions. This is causing a fault in the power board and your TV is unable to switch on.
My recommendation would be to take it to a local store and get the power board examined for flaws. Depending upon what components need to be replaced the cost of repair can be anywhere between $30-$100. Once the power board is fixed your TV will work fine. I will not recommend yo to do this at home until and unless you have expert knowledge of electronics and have the necessary equipments.
If you have any other queries then I would be glad to assist you further.Regards.Please click the green ACCEPT button if you like my help. Please DO NOT ACCEPT IF you wish to leave a NEGATIVE FEEDBACK.Positive Feedback and Bonuses are always appreciated