I have a strange problem with my 2008 iMac. At first I thought it might be the GPU as I have the dreaded Geforce 8800GS. However now I fear it may be a screen problem. The first symptom was that the brightness controls now no longer work (both on the keyboard and in sys prefs). Now when I start the machine from cold the backlight flickers on and off for around a minute, as soon as the system warms up it will stay on all day and everyday no matter what I do. When it does flicker black I can still see the desktop running in the background and the system doesn't freeze as I can move windows around etc. So does anyone know if it's the inverter cable or the inverter itself? I'm hoping it's the former as I can source the cable relatively cheaply from the states. (Unless someone knows where I can find one in the UK?) I just find it weird that the machine will function fine (sans brightness controls) once it has been running for a few minutes. Any info would be great. I've done extensive googling on the subject but cannot find anyone who describes my problem exactly. Thanks.