After i power it on, there is no pictures, no sounds too.

Have you made sure the appropriate signal source is properly connected? Could it be you have selected an invalid input source? Use your remote to cycle through the Input options. Wait 5 - 10 seconds on each option to see if a picture appears.

Sounds like some kind of data interference or glitch. Dry caps will cause interference. By not smoothing inputting signals.

Move the insulated cables for the bose away from the cables to the tv. Or go buy monster cables for the TV so there wont be interference. Sounds like power cables are interupting the picture.

Try replacing the main board

Try changing channels. Power light is on, then it means there is power coming in, but no video signal is being received (audio signal is good). Try this: turn off the TV, take out the power cable out from the power socket, wait for 30 seconds, then plug it back in, and turn it on. It should work fine. But if not, then there might be a problem inside the TV itself. Go see a local TV technician.

Check video source like DVD Player has power, check connecting cords, cable connections etc.
when TV gives menu on screen that means TV is fine and problem could be hooked video signal items.

Sounds like a Power Supply comcponent failure in the high voltage panel supply circuit.
Backlight power seems to be ok.

Can only suggest obtaining repair quotations vs. Replacement purchase?

Cable Looses signal power after 20m ... Install signal amplifier
https://youtu.be/AkiKf4G4UE0

Hello neall,

It sounds like you may have a power supply problem- (HV Power supply). I must ask if you have sound or not? If you have sound it is the HV supply only if you do not have sound the Low Volt power supply and possibly the HV power supply/Horizontal section has a problem. I would suggest that you take the TV to a qualified TV repair shop.

I hope this helps,

Thank You,

Shuttle83