The DEFINITIVE iMac 20" Screen Dimming Thread

Ok, so I've been going through this board for a while now, looking for answers to why the top half of my iMac 20" screen goes dim, after about 5-10 minutes of use. (from starting up or waking from sleep)
I have read several threads in this forum from other people who seem to be experiencing the same issue, however I have not been able to find a SOLUTION.
Do I need to send this thing away for repair? Am I going to have to spend $800 on a new LCD? I am starting to get a little annoyed when this happens. When I first received my iMac it would do it once a month maybe, however in the last 2-3 weeks it has started to go dimmer at the top half of the screen ALL THE TIME.
Could it possibly have anything to do with the sleep light firmware fix? or the fact that I have installed 2 1gb sticks of ram?
I need an answer please.

Hi again, Ryan,
The most probable cause of your problems, I would think, would be an inverter board failure (which I think falls outside the extended repair program, but check with Apple first) . The inverter board appears as a user replaceable part in the User Replaceable Parts listing
The relevant instructions for replacement of this part appear HERE .
Cheers
Rod

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