Lenovo z50/70 Laptop doesn't wake up after suspend running Ubuntu 14.10 [duplicate]

Once my laptop goes to suspend, it doesn't wake up.
I can see the LED lights saying that PC is on but screen remains black.

I am really new to Ubuntu and just recently installed it.

My laptop is Lenovo z50/70

Using Ubuntu 14.10 - haven't really done any customization on it.


Solution 1:

The problem was caused by my Nvidia Graphic card. For some reason (driver issue maybe?) it caused freezing. Disabling the card from BIOS solved the issue.

The problem still persists; maybe changing driver will solve it. I haven't tried.