LED Backlight Dead. PSU replacement or Complete Screen Replace?

My backlight just died on my iMac, opened it up and there is is an Electrical burning smell.

I can see Mac Booting up if I use a torch - so guessing its the LED driver board is fried or potentially something in the PSU.

Question 1.

Could this just be the main PSU - does it have a separate feed for the LED Backlight ?

Question 2.

If not the PSU Is there a way to just replace only the faulty board or would I need to replace the whole LCD Panel ?

This happened just 3 months out of warranty arragh !!