I have iMac 27 and screen problem on start up i have blue vertical lines, when it start i have a lot of blue dots and nothing else. when I connect outside monitor its showing the same.
Just installed lion and still the same problem when it starts blue dots, when startup in safe mode loads of blue lines and dots on the screen.
thanks for any help
iMovie (iOS), Mac OS X (10.7.3)
If you see the same thing on both the internal and external displays then that almost completely rules out a problem with your iMac's LCD display. Does the issue show up immediately when you power up the system (eg gray screen with Apple logo), or does the issue wait to appear until after the OS has loaded and you can see the icons start to appear on the desktop? If it occurs even on the initial gray screen then you likely have a hardware issue that will require servicing. If the issue occurs once you've booted then you may have a software issue.
If you boot into Safe Mode do you still see the issue? If not, then it may provide more support that there is a software issue. You can boot into safe mode by holding down the shift key right after you hear the startup tone, and then let go once the gray Apple appears on the display.
http://support.apple.com/kb/HT1455
http://support.apple.com/kb/HT1564
You could also consider reinstalling Mac OS X using the Lion recovery mode:
Yes I can see on both screen external and internal. Just when I switch on mac straith away i have blue vertical lines, after system will load up i can see loads of blue/red dots.
When I took it to apple they told me its screen, and ofered me replacment for 511pounds,
but when I spoken with the guy in service shop he said if its on two screens its logic board and it will cost 290 pounds.
so I dont what to think about it???
Thanks for your help
iMac 27 blue strips, after loading blue screen or load of blue dots.
