Boot light on when power on.

[xxcutive]

Please help me I have a Jynx Ultra HD V2 and now it got stuck on boot light. I ve been try everything to get it back working but no luck. I also bought USB to serial cable but still not reading when loading. I want to get a null serial cable but all my PC or laptop doesn't have a serial port. Any suggestion.
Thanks for reading

[loctite]

open box and look at the small power board with power lines for the tall round capacitor (1000umf 24v)in front for bulging, or any others. It regulates power input. tv repair shops have a drawer full. disconnect ribbon cable from large board,power connector,4 screws and take it for cap replacement, if damaged.