Nook HD screen went dim

No. It;s likely your battery is failing as the device is pretty old.

Nook HD will not charge, or turn on. ' Nook Support Forums

https://bookclubs.barnesandnoble.com/thread/9608

Barnes & NobleApr 6, 2013 - I have a pretty new nook HD, it was a Christmas gift. ... The device stillwon't turn on. ... Sometimes it takes up to 1/2 an hour to turn on if the battery charge... Yes, the indicator light has always briefly flashed green then orange on my device. ...But you said plug it into wall charger first and leave it overnight. Nook HD charged for days, green light, still won't turn on! - Nook ...
Feb 27, 2014
My Nook HD won't charge or turn on! ' Nook Support Forums
Jan 30, 2014
Nook HD won't charge ' Nook Support Forums
Jun 29, 2013
Nook tablet won't power on ' Nook Support Forums
Mar 13, 2012
More results from bookclubs.barnesandnoble.com

indicator light changes from yellow to green
It died while on the charger

Barnes & Noble Nook HD
Will not take a charge

You might have to hard reboot ur nook

You screen has separated and you will not be able to fix this one.

You will need to "reboot"
While pressing down the Nook button (upside down u on the front of the tablet), press the power button on the side. You will need to hold it for couple of seconds.

my nook tablet shows the green light that it's fully charged but when trying to turn it on nothing happens the screen does not com on or the nook symbol does not light up . can any one help me out here

There is no way to edit the screen ratio on the new iPad or any iPad for that matter. They went with 4:3 because the majority of users use the device to browse the internet and read e-magazines or e-books on it. As you know the screen gets cut off when you go to fullscreen or it has those annoying black bars above and below.
If you're looking to watch video do it on a computer or your TV. The new iPad isn't made for heavy video watching IMO.