iMac Intel 27" EMC 2429 display goes black

I've got what appears to be a relatively common problem - the screen goes black, but the machine doesn't turn off. It has been intermittent and increasing for about the last six months. It's not an overheating issue - happens seconds from start-up and when the machine is ice cold. I've done the "flashlight" test - shined a light through the front of the display, and can still see a faint image of the desktop.

The support forums are a little confusing, so before I go buying parts I'm looking for a little clarification:

I've been told that the part I'm looking for is called the "Converter board" - is this the same thing as the "LED Back-light board"?

Is there only one back-light board?

Is there an additional part called the "LED Driver board"? If that's different than the Back-light Board, I'm assuming my problem is in the latter (the Back-light) rather than the LED Driver, and I assume that the flashlight test proves this. Correct?

Thanks - these forums are truly a amazing, thanks to everyone for sharing their knowledge...