Hi, my name is XXXXX XXXXX I have been in the home improvement and repair field for 20 years. I will be glad to help you today. I have tinkered with those tvs before. I find they have a lot of troubles with the power supply. If you have a bit of experience with working on electronics and have some experience with soldering electronics you will likely find a bulging capacitor on the power supply. If you do not find a bad capacitor then the power supply itself has a failing component in it that cannot be replaced. You may find a replacement power supply on Ebay for a reasonable price if this is the case but be sure if you take that route that you match the part numbers exactly. Be sure that the power has been discharged before you work on it also. Even after unplugging it there is a lot of voltage still stored in the capacitors.
A capacitor will be perfectly flat on top if it is a good capacitor. A bad one will be bulging or leaking as pictured.