Chosen Solution
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 !!
Turns out it was a Capacitor on the Logic Board that was at fault and thankfully not the whole screen. Capacitor is being replaced
