Macbook goes black
Okay now its 2012 and this thread still seemed to have no solution but here is my fix.
Having tried resetting the SMC as suggested, and then dismantled the computer I found the LCD was still fully functional but the back light was off, there was no flickering on opening and shutting the screen and I checked the leads were intact, then by accident while reconnecting the leads I found it would sometimes work on minimum brightness if switched on multiple times but would go back if the illumination was increased. I presumed it was the inverter malfunctioning but so many people have had no success with replacing that on this forum, I doubted it was the answer. Then this morning laterally thinking about some people wondering about the firmware update, on a parallel thread in macrumours I did something irrational.
I rebooted on an older snow leopard system on an external while the screen was functional enough to do so and voila full brightness! Then I rebooted on another newer backup OS voila! Finally back to the internal 10.6.8 and voila!
So here I am with a bright display which is good for sleep and wake - the machine is still half dissembled but now finally seems stable.
Since this did seem to fix it what does this actually mean about this recurring problem for many users? How does rebooting of another OS fix this fault so it seems to be fixed on the original OS?