iMac screen black out

Hi Nick,

I think the first thing to do is Boot into Safe Mode (you probably already are) and uninstall Wacom Tablet by doing the following:

1) In Spotlight, type: tablet

2) Click on: Wacom Tablet Utility

3) Under Tablet Software click on: Remove

Follow the prompts. Then try restarting normally and let me know how you get on. 🙂

Max.

First off, thanks Max!

I did just that but seems to have no effect.

My screen now will only go on for 5 seconds and goes black soon after, meanwhile my external display is working fine.

So, are you able to boot normally and run the following command from Terminal on your external monitor?

kextstat | grep -v com.apple

If so, please post the output. Also, if you disconnect the external monitor and boot, does the main screen still go black after 5 seconds?

Yes I'm booting perfectly fine on my external display.

Nick-Zipagans-iMac:~ nickzipagan$

Nick-Zipagans-iMac:~ nickzipagan$ kextstat|grep -v com.apple

Index Refs Address Size Wired Name (Version) UUID <Linked Against>

57 0 0xffffff7f80b74000 0x4e000 0x4e000 at.obdev.nke.LittleSnitch (4350) 3FED6E04-2313-3380-BF90-C0896531D3A1 <5 4 3 1>

133 0 0xffffff7f81b64000 0x3000 0x3000 com.eltima.ElmediaPlayer.kext (1.0) ED5E3CAC-81B9-934D-8CC3-3E28A072632C <4 1>

Nick-Zipagans-iMac:~ nickzipagan$

Little Snitch is okay, but Eltima kexts don't play well with the last two betas. Please run the following commands for a clean uninstallation of the El Media Player software:

• killall -TERM Elmedia\ Player
• launchctl unload /Library/LaunchDaemons/com.eltima.ElmediaPlayer.daemon.plist
• kextunload /System/Library/Extensions/ElmediaPlayer.kext
• sudo rm -f /Library/LaunchDaemons/com.eltima.ElmediaPlayer.daemon.plist
• sudo rm -f -R /Library/Application\ Support/ElmediaPlayer/empdaemon
• sudo rm -f -R /System/Library/Extensions/ElmediaPlayer.kext
• sudo rm -f -R /Applications/Elmedia\ Player.app

Then reboot and see what happens...

I just tried this and no luck unfortunately.

Hmmm... Did you try booting without the external monitor connected as I asked above? And could you re-run:

kextstat | grep -v com.apple

Last login: Sat Aug 29 23:06:12 on ttys000

Nick-Zipagans-iMac:~ nickzipagan$ kextstat | grep -v com.apple

Index Refs Address Size Wired Name (Version) UUID <Linked Against>

61 0 0xffffff7f80b74000 0x4e000 0x4e000 at.obdev.nke.LittleSnitch (4350) 3FED6E04-2313-3380-BF90-C0896531D3A1 <5 4 3 1>

Nick-Zipagans-iMac:~ nickzipagan$

Good. EltimaPlayer is removed. If you want it back I'd suggest waiting until the final release of El Capitan before reinstalling because, as I mentioned earlier, Eltima kexts have been causing failed bootups recently (mostly SyncMate though).

Thank you so much Max! I think it might be a hardware issue but I've gone away for vacation and came back to find it working again so I really dont know. I will drop it off to apple genuis at some point.

I've dug a little deeper into this (I had forgotten some of the specifics of the issue you'd been having) and I realise now that it was not kext related in your instance (I had assumed it was because that's been the case for about 90% of Macs with similar issues that I've helped troubleshoot).

The problem was one affecting a much smaller number of people where Apple's own display drivers were causing issues on iMacs and Mac Pros that had a multiple monitor setup. The most recent Beta fixed that however, and it is still fixed in the GM. Your Mac must have automatically updated while you were away and that's why you don't have the issue anymore.

So same conclusion - I doubt you have a hardware issue - but the cause turns out to have been the OS X beta and not 3rd party software.

-Max

Hi Max,

I think I might actually be a part of the larger group with faulty hardware/graphics because I'm seeing more and more of the symptoms aline. When the screen brightness is up from 50% the screen blacks out frequently, when I turn it down below 50% it works fine and anytime I increase while its working properly it immediately blacks out again.

Yes, I concede that does indeed sound like a hardware issue. In general I'm loath to conclude that because it's the lazy way out: "Oh, it must be a hardware issue" sometimes = I can't figure out what the problem is so let's blame the hardware. This is particularly true when it comes to a beta OS. But yes, in this case I think we can conclude that the issue is hardware.