My dog attacked the tv, I think he was following a rabbit. Now I have a smart tv with a broken screen that cannot be fixed. Thus I wish to turn it into a dumb light as in a false window. I have opened it up and removed the screen and I see two electronic boards internally. Can I discard the two boards and just attach a 240v switch to the incoming supply to run the background lights?

 

I was inspired by DIY Perks Youtube channel to have a play with an old TV backlight.
Have a look at this posting of my efforts that includes a link to the diyperks video.
http://www.sadarc.org/xenforo/upload/index.php?threads/old-tv-as-work-light.425/#post-3350

If you can, just use the existing power board and toss the TV one. The power supply board will usually have the back light driver on it. The trick is to see how it is turned on from the TV board. My post shows how I fixed this TV.
It is well worth doing as the light is very good.

 

No. The lights require an electronic driver.

 

Before you remove any components; measure voltage and current the backlight(s) take to work, and where in the power supply board is their source connector(s) Write that on the nearby metal chassis.
I have 3 ceiling lights from defunct TVs, 2 of them run from a purchased supply matching the requierements. Another from its own original internal supply.



Did not find the images installed flush on 'acoustic' ceiling tiles

 

Have you confirmed there are working backlights? Do you know if it's fluorescent or LEDs?

As @BobTPH notes, you'll need to identify and use the power supply or another that provides the same requirements.

 

On one of the TVs I use for an work light, I could not use the original power supply so a suitable unregulated supply was made and each string of LEDs has an added constant current regulator as shown below.

Using an LM337 -Ve regulator (NOT an LM317) has the advantage that the tab is the -Ve connection so it was just screwed down to the TC frame as a heat sink.
First you need to determine the voltage the LED strings need, then ass maybe 10V to that number so the LM337 has some headroom.
This TV had 4 strings of LEDs so there are 4 LM337 regulators installed.