As I have observed this happens when I use the laptop the following day after it was shutdown for a couple of hours. "I mean the first use of the laptop during the day" for example,when I open the laptop at 8am it freezes with the same garbled image, after reboot the laptop runs fine until 5pm in the afternon. The next day when I open the laptop it freezes again. I'm really puzzled about this. I think this happens when the laptop is cool, but thats just my thinking.
I've also observed that when I'm connected to the internet the freezing often occurs, specially when I'm using Facebook. I've tested the memory 3 times using memtest and its ok, I also tested the hard drive and found no bad sectors or any errors on it. I also connected the laptop on external CRT Monitor the same thing happens, both the external monitor and the laptop monitor displays garbled image at the same time. Does this mean that the laptop monitor is not the culprit? I'm guessing that the built in video is the one causing this, and my bad, its soldered into the motherboard. Please help me on this as I do not want to be blamed for the laptop's problem. Tnx in advance