powerbook 12in and external display prob

Hi all,


I have just purchased a 19in widescreen display for my 12 in powerbook (not core duo). I have a few questions about it.

After hooking it up, I get some apparent horizontal scan lines across my 19in screen, anyone had this issue before?

Also, is there just a way to have to mac display turn off, and only run on my 19in?


Thanks

I would take the screen back if it has horizontal lines. I dont know of a way to turn to screen off but you can take the brightness all the way down.