Actually his onboard LAN port has got some burn marks on it. He said some routers of Nivyah broadband went kaput after a lightning strike and so did his onboard LAN port.
It's the PSU. I am writing this while using the same system that refused to boot. Plugged in the same iBall 400W PSU and it's running like a dream. Now, I need to find a good PSU that can power my rig. Opening a new thread for that. Thanks everyone for your suggestions.