Blackscreen since startup, but work with HDMI cable on my TV
I've a problem with my superb iMac 27¨ late 2009.
But since yesterday, with no reason, the main screen doesn't work.... the screen stay black during startup, then when OS X started, and as I use the external HDMI port with my TV, I can see the desktop and I can work with my iMac.
However the main screen remain black ....
I saw many answers on the web site, but nothin regarding a black screen from the beginning of the power-on.
Do you think that changing the LCD will works?
Do you have any idea, excepting resetting CMOS, NVRAM, SMC? (as I can see any thing on my main screen).
I've a bluetooh keyboard, I've only a Windows USB keyboard, do you think I can use it to press some command during startup?
Is this a good question?