Good morning, alot of TV's have rather complex circuits in them these days which gives less tolerance for faults, this combined with a drive to reduce costs by the consumer, products are being produced cheaper and hence lasting less time before requiring a repair.
The fault sounds likely to be hardware related, the good news is all modern TV's are modular so the power board can be swapped out, rather than needing to replace one large circuit board.
Before suggesting you book your TV in for repair, I would start by leaving it switched off and unplugged for 5 minutes, disconnect all cables (HDMI, USB, Coax) from the TV, just leaving the power lead, and then try and turn it on using the power button the the TV.
Then please let me know if the status light comes on, if the link blinks, and if the TV comes on?
This is looking like a power board failure so will need to be taken to a service centre, if you can advise me your post code I can recommend a suitable service centre for you.
The one thing worth checking before taking it to a service centre is that the fuse in the plug hasnt blown, if you have a spare mains cable try and plug that in and see if the TV comes back on, or you could swap over the fuse in the plug.
If changing the cable \ plug fuse doesnt resolve the issue, I would suggest you drop it off AV Tech who are at Unit 6, Whisby Way Business Centre, Lincoln, LN6 3LQ, their phone number is ***** 302565.
They charge £10 to provide a quote, but have advised the Hitcahi parts are relatively cheap so it should be a worthwhile repair, however also mentioned that they probably wont get back to you until early next week due to the back log.
I havent heard back from you in the last few days, and just wanted to check if you still require assistance, I would appreciate it if you could rate the service received.