possibly motherboard the first signs i had of my motherboard dying was when my laptop would go into sleep mode and then i would get color blotches and lines all over the screen when i reactivated it, thats if it reactivated. Thats different then black dots so you may have a different problem than I had.
Yup, when my laptop had a bad motherboard that was also the first sign. Hopefully we don't wig you out. I'd recommend some serious testing on both A/C and battery power to see if other problems exist/begin.
i have the same graphic card and i had the same problem. On resuming from sleep appeared color lines and the screen was unreadable.
I was using the Omega Drivers 2.5.51 and i try to upgrade it to last version 2.5.58. The problem continued.
What i did was to uninstall all graphic drivers and graphic-related software in the laptop (hydravision, multires, radlinker...) and also the registry keys and i made a clean install of the Omega Drivers 2.5.58 and now it works perfectly!