Computer screen goes blank, and if sound is on it plays white noise

At first I thought it was an overheating issue, but it happens pretty much right away sometimes, with the laptop almost stone cold. It only seems to happen if I attempt to multi-task, as in have a browser open while listening to music etc. And as I said, if sound is playing it becomes just white noise, fuzzy. If theres nothing playing then it remains quiet. The screen goes black, but is still lit up. The only way I've found to stop it is to turn the laptop off and on again by holding the power button, but it's incredibly annoying as I lose anything I have open at the time, so I'm hoping maybe there's an solution to this without having to replace it.