Something is definitely wrong with you Mac machine’s display and that is the reason you have landed on to this page. I have listed out three steps, (which could prove to be three different ways also), as any one of these steps can fix this issue on its own.
If you have woke up and found that your Mac’s display is distorted, or you are not able to understand if your Mac is running or not because its display is not working. Let me start with the methods.
How To Fix Display Problem On Mac – Fix Distorted Display
Method One – Reset SMC and PRAM / VRAM
They say that it won’t fix many of your problems, but you can still give it a try as it would hardly take any time. And the fact that this method won’t do any bad to your machine makes it a MUST TRY method.
To Reset PRAM / VRAM, you need to hold Command + Option + P + R until your Mac reboots. And this would clean info like startup disks, screen resolution, speaker volume.
Then try to reset System Management Controller (SMC) and see if it fixes your Mac’s display problem. This would basically every control on your Mac, from its power to fans. And there is a very good probability that both these resets would help you fix many issues. To reset SMC, put your Mac on charge, hold Left Shift + Control + Option + Power buttons for 10 seconds and then restart your Mac.
Method Two – Hardware Test
This might not fix any of your Mac’s issue but it would surely suggest you if there is a problem with the hardware. Infact, this is the first thing that you should be doing because before you actually end up wasting so much of time on fixing something and then coming to know that the hardware itself was faulted.
Restart your Mac and hold the D button until the Apple Hardware Test begins. On Snow Leopard, it does not starts straight away, as you need to put the Installation Disc first.
Once the Apple Hardware Test window is up, click on Basic Test. Let it complete and see if it shows any failures. If it does not, then click on Perform Extending Testing, which would take an hour or so to complete. If it informs any hardware failure, then take your Mac to Apple Support Center and if it does not, then you need to explore new ways to identify and fix the problem.