Yosemite 10.10.3 Second screen big problem

I have the same issue. iMac with HP w2207h external monitor connected by mini display port adaptor to HDMI cable. It was working until I did a clean re-install of Yosemite trying to fix another problem. After that the HP monitor would not display after wake from sleep. The Mac was detecting it, since I could go to Displays Preferences and Gather Windows. I have now discovered that, if I set the HP to Scaled at about 85% and choose 1080i it works. Unfortunately the resolution is fuzzy, which I can fix by changing back to 1080p, but then the monitor won't wake after sleep unless I Gather Windows and change the resolution to 1080i again.

Just found this thread: https://discussions.apple.com/thread/6986147. So it seems the problem is that the 10.10.3 update causes problems with (older) Macs with ATI video cards (such as my mid-2010 iMac).

I did the same. I rolled back to 10.10.2. I made a clean install from 10.10.0 to 10.10.2

However the problem with permissions in private/var/db/displaypolicyd was there in every of these updates. Finally I tried the below solution.

The trouble with permissions is fixed.

BAthompsoniteApr 5, 2015 8:20 AM
Re: Permissions problem in displaypolicydin response to lplacencia

Use the Go To Folder feature in the finder to navigate to private/var/db/displaypolicyd. Delete the folder named displaypolicyd, which should be empty. It was empty on my computer. Go to your disk utility and verify the disk permissions. It should no longer pop up in the results. Reboot your computer and then run the verify disk permissions in the disk utility again just to make sure it is still not there. I did this last night and now my MacBook Pro wakes just fine from sleep mode, it restarts just fine, it shuts down just fine and hasn't randomly blacked out since last night. I'm running a Late 2011 15-inch MacBook Pro.

So far everything works fine.

10.10.3 the worst update that cost me 3 days of headache

Anyone knows what Apple was attempting to achieve, if anything, with 10.10.3 in the graphics department?

A

I hope I don't have to do a clean install and then be stuck with 10.10.2 (my mid-2010 iMac with ATI video card (ATI Radion HD5670) stopped detecting my Sony LCD-TV). I have so many applications set up just the way I like them and I have Windows 8.1 via Parallels virtual machine as well. Now I know with my SuperDuper backup and migration assistant I would not have to start over after a clean install but it would still be a lot of work. Still, I would hate being stuck with 10.10.2 and not being able to update to any future versions. Therefore, for now, I will keep on hoping that either Apple slips a fix into 10.10.4 (or even into 10.11) or someone will figure out a hack to fix this issue (obviously it would either have to be a software hack to the 10.10.3 ATI video driver settings or some DIY trick to the HDMI cable where I was able to get my iMac recognize but not actually enable my Sony LCD-TV my covering a pin in the HDMI male connector going to the Sony).

After zapping the parameter ram(pram) , disabling tMST(by disabling displayport 1.2 support in monitor settings) and selecting a custom resolution in SwitchRes X I'm back with what I initially had in OS X.

I perceived problems also in BootCamp recently. I booted into Windows to access monitor settings,as OSD is only available when there is a signal to the display. It seems that I broke MST by in error accepting the AMD Catalyst 14.12 update(which clearly stated that it was not meant for BootCamp systems).

Suddenly, in Windows 7 I could see my Dell UP2414Q monitor recognized as tow distinct displays.

Purging my Windows installation of any AMD software and installing the next to last Catalyst bundle, I finally was able to restore a working 3840x2160@60Hz resolution.

Hopefully, Apple will enable MST in a working manner for mya Radeon HD7950, but I feel that would be hoping a little bit too much.

A

This looks promising, however there does not seem to be such a folder in Yosemite. Can anyone help with this?

TIA

The displaypolicyd is a hidden folder. You may check the whole thread Permissions problem in displaypolicyd

I don't know if this solution works in 10.10.3 for everyone. For now (back to 10.10.2) it is working.

Thanks. It is such a mess, and I don't have time to go into this, fascinating as it would be. I have another computer running Ubuntu, which can show an image on an external monitor, which I am using now for work. This kind of issue could lead to Apple losing customers, but I guess they don't care about computers any more, just fancy watches.

Another upgrade solving this should have been released within two days of the problem becoming evident. There is simply no excuse.

And now there are no update to fix it. Im thinking for solding my iphone and mac for another brand, i dont know what to do))

Mac Pro 2013. No prob with my main Dell 30" display, after updating I've had constant issues with my second monitor (Dell 24"). Flickering. Drop outs. 2nd Monitor just flat out stops working sometimes until it's plugged in again. Yosemite has problems.

Just started using a Dell U2211H as an external monitor connected with a non-Apple mini displayport to VGA adapter to a Macbook Air 2012 (10.10.3) and get the same intermittent flickering issues. Had a lower res Samsung before which worked fine.

Tried to update the firmware of the adapter with this update: About the Mini DisplayPort to VGA adapter firmware update - Apple Support

but it errors out saying that it can't find an adapter to update. I reckon this is because I'm not using an Apple original adapter, but it may help other people with this issue.

tried different thunderbolt port already...? regs, coen

Hey guys,

I don't know if this fix will work for you, but if you're having this display issue with any external display devices give it a try.

I was using a MacBook Pro with a Dell monitor hooked up via Thunderbolt->VGA adapter. It was working fine prior to OS X Yosemite 10.10.3 update, and stopped after. In the display preferences the monitor was recognized, but black with no visual display. No amount of settings, rechecking cables and connections or other voodoo was working. I did some research here on the forums and found others with similar issues, and no apparent solution.

As the Windows adage goes, if something isn't working, 'Try turning it off, and on again'

I unplugged the Thunderbolt connector from the MacBook, turned the computer completely off, waited about 1 minute, plugged the adapter back in, and powered on the system again.

Upon booting up, the monitor was again recognized, and was properly displaying video. I don't know if this will work for other devices, but I hope that it will help someone out there.

Cheers!

I have the same setup, 2012 rMBP and HP 23w monitor. The only way I can get it to work is Thunderbolt to VGA. The DVI and HDMI do not work for me. 😟