I purchase the sony z series (PCZ115GA) in may, i have hardly used the laptop but in july my monitor konked off. When i took it to Sony sevice centre, they told me because of misuse the monitor display had internally cracked from inside and hence had to be replaced, which was not under covered under warranty so i had to spend around 200kd (abt 500 dollars) to fix it. now after a few months again my monitor keeps flickering and i am worried the same problem will repeat and even though it is under warranty period , i will have to spend on the laptop. i have previously using Tosiba satellite for more than 5 years without any complaints or issues
It sounds like when they installed your new display that they didn't attach all of the connectors firmly. I suggest you return to them and have the Sony tech's verify that everything is properly (securely) fastened. If so, then the motherboard is likely defective and would have to be replaced under warranty (the video system is integrated onto the motherboard and can't be replaced by itself).