Z's Across my Screen?

[EnzoAmata]

I have a 27" iMac and I had open a few programs, then three z's came across my screen and it froze, screen went black, came back on but the machine was running really slow, forced me to do a restart.

What was this? I didn't know what to Google for this, tried "ZZZ iMac" + "Z's across iMac screen" I have no idea so asking you guys.

 

[GGJstudios]

I have a 27" iMac and I had open a few programs, then three z's came across my screen and it froze, screen went black, came back on but the machine was running really slow, forced me to do a restart.

What was this? I didn't know what to Google for this, tried "ZZZ iMac" + "Z's across iMac screen" I have no idea so asking you guys.

Sounds like it was just catching a few Zs. Are you sure you didn't put it in sleep mode?

 

[EnzoAmata]

Sounds like it was just catching a few Zs. Are you sure you didn't put it in sleep mode?

I was watching a YouTube Clip. I hit no keyboard keys. It had that grey rounded cornered circle that the volume has when it gets turned up and down from keyboard shortcuts but it was Z's

 

[winter kid]

same issue

this just happened to me on my MacBook. It's been having issues when I run it off the battery; it will just turn off randomly. but it was plugged in when the Zs just appeared and the screen went black. I pushed escape and the screen returned.
there is a warning in system preferences, though, that says I need to service the battery. I guess it's my fault somehow

 

[Jtepp]

I have a 27" iMac and I had open a few programs, then three z's came across my screen and it froze, screen went black, came back on but the machine was running really slow, forced me to do a restart.

What was this? I didn't know what to Google for this, tried "ZZZ iMac" + "Z's across iMac screen" I have no idea so asking you guys.

The same thing happened to me, twice now. I thought it might be because of the app MacID but im not sure if you have that app. I noticed that it happened after i tapped the trackpad on my macbook...

 

[patternjake]

Sounds like the graphics processor is over-heating, which can cause artifacts (which you describe as Z's)
Switch to HTML5 player on YouTube instead of Flash if that is what is being used, Flash is terrible for overheating video cards.