How to switch off iMac screen and only use an external monitor

[siam]

I know I'm going to sound foolish and the answer to my question may be simple but I can't think straight at the moment

On my 2008 24inch iMac the screen has a problem ( dead pixels ) and I will get it replaced in the future , in the mean time I have a very nice large external monitor connected to the iMac which I use ok, what I am looking for is a way at first when booting up , to be able to see both the iMac's screen and the external monitors screen , then some how shut off / make blank the iMacs screen only leaving the external monitor on ?

any advice or comments please

Thanks

 

[iSKW]

I am 99% sure that you are not able to disable the iMac screen. In fact i think there was a topic just like this one a little while a go

 

[siam]

I am 99% sure that you are not able to disable the iMac screen. In fact i think there was a topic just like this one a little while a go

Hi thanks for the info, I am trying to find a way to just make the iMac screen
go dark , not necessarily turn it off, Ive been told that Shades can independently dim either display to black. , but sadly shades does not seem to work with display Mirroring turned on ,which is what i need to see the desktop on the external monitor , not too sure what to try next

 

[mmulin]

Hi thanks for the info, I am trying to find a way to just make the iMac screen
go dark , not necessarily turn it off, Ive been told that Shades can independently dim either display to black. , but sadly shades does not seem to work with display Mirroring turned on ,which is what i need to see the desktop on the external monitor , not too sure what to try next

I have no iMac but you can try these two options if nothing better comes along:

- perhaps Shades is able to dim just one display in extended mode; in that case configure it that your external screen is the main application screen
- again, use the extended mode and put a black wallpaper; i understand this is not entirely satisfying but may be enough for you

 

[siam]

I have no iMac but you can try these two options if nothing better comes along:

- perhaps Shades is able to dim just one display in extended mode; in that case configure it that your external screen is the main application screen
- again, use the extended mode and put a black wallpaper; i understand this is not entirely satisfying but may be enough for you

Thanks for that it worked out OK , its much appreciated