Hi, thank you for contacting JustAnswer.com. My name is Russell. I will do my best to provide the right answer to your question.
When a device comes up blank or with black screen, it seems quite a block to getting anything done with it.
And sometimes that's just what it is: the device is 'broken', and that's that: it has to be repair-serviced, or replaced.
In this case, the first thing to do is, to observe, are there any signs of life anywhere when you first switch the TV On after it has been Off for a while? does the power light flash even briefly? Do any lights flash anywhere on the TV, for instance, do you get a repeated flash code?
The next thing to observe is, Are you using the right power outlet to plug in the device? the other connections are nothing much at this point - the thing to do is to make sure the power path into your device is A-OK and uninterrupted.
1. check the outlet, using another device (a small reliable device, e.g. a lamp) to make sure it is providing power, and has not been GFI-interrupted and that the circuit breaker for that outlet has not tripped (if so, it will need a reset.)
2. check the power cord to the TV. Is it OK along its length? is it firmly plugged in to the TV (if it is the removable type of power cord) ?
Let me know what you find out, please. I will advise you further.