My Macbook Air, Freezes whenever the screen timesout

I'm not able to use my Keyboard and my touchpad sometimes. I noticed it happens only when I close my Macbook and open it again, also during screen timeout. The power button seems to be working. I've already tried the following.

• Resetting the PRAM - Ctrl + Opt + P + R during power on.
• Reset the hard disk
• Safe mode

The issue seems to persist in Safe mode as well.

Please let me know, what could be the issue and what would have to be done to fix the same.

Thanks