Headless Mac Mini Black Elements (blocks) when screen sharing

[PaulKemp]

Did you read the articles quoted above? All you need is an adapter to fool the Mini into thinking it's connected to a monitor.

Did you read my posts above?

I read the articles, but they use a VGA adapter to fix this. The 2011 version ships with a HDMI-DVI adapter. And that particular adapter does not have the analog signals used in the VGA adapter to fool the mini into thinking it has a monitor connected.

In my case it was way easier to just connect it to a monitor in a 2nd bedroom. And the performance is way better now that it has a head! Way way better.

 

[palebluedot]

Did you read my posts above?

I read the articles, but they use a VGA adapter to fix this. The 2011 version ships with a HDMI-DVI adapter. And that particular adapter does not have the analog signals used in the VGA adapter to fool the mini into thinking it has a monitor connected.

In my case it was way easier to just connect it to a monitor in a 2nd bedroom. And the performance is way better now that it has a head! Way way better.

FWIW OS X has become TERRIBLE with remote sharing (VNC), esp. on headless machines. There are tons of threads about the problems, from Lion and ML, with it on MacBook Airs and Pros as well.

Which IMHO is ridiculous. Windows can go headless without a second thought. It really isn't complicated, it's just a restriction implemented by Apple either by choice or through negligence.

 

[PaulKemp]

Which IMHO is ridiculous. Windows can go headless without a second thought. It really isn't complicated, it's just a restriction implemented by Apple either by choice or through negligence.

Agree. The fact that the GPU is nerfed when using VNC is just ridiculous. Especially with these minis, they are perfect for beeing headless!

Anyway, the problem is solved for me (its now connected to a monitor) and I've learned about this!

 

[ActionableMango]

Acceleration is disabled when no monitor is detected. There is a way to fix this in software; I don't get the black screens and huge lag any more.

Unfortunately there are many steps and I'm not in front of my mac, so they are a bit vague:

Get xcode from the app store.
Open xcode and there is a place to get additional packages.
Get quartz debug.
At some point you'll be taken to the Apple website and you'll have to register as a Mac developer (free) in order to download quartz debug.
Start Quartz Debug.
Enable Quartz Extreme and Force Quartz GL.

Restart your screen sharing session.

Granted, this problem for me was intermittent. But I've been going a solid 5 days now with no black screens or splotches, and only very slight lag similar to Windows screen sharing.

 

[philoouu]

Acceleration is disabled when no monitor is detected. There is a way to fix this in software; I don't get the black screens and huge lag any more.

Unfortunately there are many steps and I'm not in front of my mac, so they are a bit vague:

Get xcode from the app store.
Open xcode and there is a place to get additional packages.
Get quartz debug.
At some point you'll be taken to the Apple website and you'll have to register as a Mac developer (free) in order to download quartz debug.
Start Quartz Debug.
Enable Quartz Extreme and Force Quartz GL.

Restart your screen sharing session.

Granted, this problem for me was intermittent. But I've been going a solid 5 days now with no black screens or splotches, and only very slight lag similar to Windows screen sharing.

Hello

Can you give us more details about it once you are in front of your Mac ?
I never heard about such a thing in any other forums before and it looks a very clean solution.
If this works this is definitely the best solution !!!
Thanks for your help
philoouu

 

[ActionableMango]

Hello

Can you give us more details about it once you are in front of your Mac ?
I never heard about such a thing in any other forums before and it looks a very clean solution.
If this works this is definitely the best solution !!!
Thanks for your help
philoouu

Which step did you have trouble with?

 

[philoouu]

Which step did you have trouble with?

I installed everything as you said. It does not solve my issue. I have one application that is not working properly when a screen is not connected physically !
Running the debug for me is not tricking the Mini Mac even after a restarting Share Screen.
Well let us hope it is not Apple decision to keep it like that.
Thanks
philoouu

 

[ActionableMango]

I installed everything as you said. It does not solve my issue. I have one application that is not working properly when a screen is not connected physically !
Running the debug for me is not tricking the Mini Mac even after a restarting Share Screen.
Well let us hope it is not Apple decision to keep it like that.
Thanks
philoouu

You can try an EDID emulator. That worked for someone else in a different thread. I don't know if it will fix the specific issue you are having with that one application.

 

[philoouu]

You can try an EDID emulator. That worked for someone else in a different thread. I don't know if it will fix the specific issue you are having with that one application.

Thanks. I will probably wait for some kind of fix.
Do you have any idea why Apple would not let people using properly Share Screen on headless Mac Mini. Is that on purpose or a bug ? For me it looks more like a bug so it should get fixed at some point. One of the main selling point of the Mac Mini is its headless use.

 

[Darby67]

Thanks. I will probably wait for some kind of fix.
Do you have any idea why Apple would not let people using properly Share Screen on headless Mac Mini. Is that on purpose or a bug ? For me it looks more like a bug so it should get fixed at some point. One of the main selling point of the Mac Mini is its headless use.

I wouldn't hold my breath, it's been a normal, albeit bothersome, thing for several years. I would tend it disagree with you on the main selling point supposition. Although many of us, myself included, have a mini that is headless, I have yet to see any Apple marketing material that lists that as a selling point.

 

[mmomega]

I also went through the random black screens on a 2010, 11 and '12 Mac Mini when screen sharing.

I remembered that I had Apple's "Remote Desktop" app from years ago, I just never used it much because screen sharing worked for the most part.

So I installed the Remote Desktop app on my iMac and then the Remote Desktop client on my Mac Mini and I haven't experienced a black screen event in a few months.

Hopefully this can help some other folks where this issue was getting annoying.

 

[T'hain Esh Kelch]

Thread necromancy!

Have any of you have trouble waking your Mac mini properly, and have had it remedied, by using this resistor/adapter trick? Especially using the Apple remote.

 

[TitouDoc]

The MiniDP-VGA dummy dungle work fine on my MacPro !
To the one who make one, what resistor do you use ? I use a 85 ohms.
The MacPro find a 800x600 VGA screen by default, I have to set upper resolution manually. Will resistor value change anything ?

 

[willgreene99]

With aTB display connected, remote performance was good. I disconnected the Tb display and tried the Apple Remote Desktop but that too also left me with the screen not refreshing. I'll try the quartz method to see if that works.

----------

Acceleration is disabled when no monitor is detected. There is a way to fix this in software; I don't get the black screens and huge lag any more.

Unfortunately there are many steps and I'm not in front of my mac, so they are a bit vague:

Get xcode from the app store.
Open xcode and there is a place to get additional packages.
Get quartz debug.
At some point you'll be taken to the Apple website and you'll have to register as a Mac developer (free) in order to download quartz debug.
Start Quartz Debug.
Enable Quartz Extreme and Force Quartz GL.

Restart your screen sharing session.

Granted, this problem for me was intermittent. But I've been going a solid 5 days now with no black screens or splotches, and only very slight lag similar to Windows screen sharing.

I assume that you are doing this on the Mini?

 

[ActionableMango]

With aTB display connected, remote performance was good. I disconnected the Tb display and tried the Apple Remote Desktop but that too also left me with the screen not refreshing. I'll try the quartz method to see if that works.

----------



I assume that you are doing this on the Mini?

Yes, this is on a Mini. But I have to take back my early report of success. I do experience intermittent black screens. The longer it has been since my last session the more likely it is to occur. I did not experience this earlier because I was using the Mini so often during setup and configuration of the software and services I needed.

Even if there is an improvement, the quartz method is a hassle anyway because you have to activate it each time after logout/login or reboot, although that could probably be automated.

I do have another idea but I haven't had the time to try it yet. The hardware dongle method is just spoofing an EDID for a monitor that doesn't exist, and this is reported to work just as well as having a monitor hooked up. The thing is, there's also a software method for forcing an EDID when no EDID is detectable, and since that is free, I'm going to give it a try some day.

 

[Owdee]

mac mini headless black screen

Hi.
first post here...

Jus wanted to share that I have beeen struggelign for a while with setting up a headless mac mini running snow leopard 10.6.8 and accenssing it from my mbp running mountain lion.
Screen in mac´s own screensharing app woks fine but when the mini goes to sleep, sceensjhring cant wake the screen up. just stays black with a cursor. file and everything are accessible with finder but no screen.... tryed everything and I mean everything

so I came across "team viewer" http://www.teamviewer.com

works!!! free for personal use!!!! absolutely amazing and easy to set up and use!!!

/hep!

 

[j-beda]

maybe a VGA dongle is useful

I came across this posting: http://blog.macminicolo.net/post/33839671756/build-a-dummy-dongle-for-a-headless-mac-mini

"A dummy dongle mimics a monitor being attached to a Mac. It will force a Mac to load the video driver and take full advantage of the GPU. "

Is there any way to trick the computer into using the GPU even without hardware attached? Yes there seems to be one I just found a post at https://discussions.apple.com/thread/4155369?start=15&tstart=0 which references a display driver used as part of Avatron Software's "Air Sharing"/"Air Display" display sharing system.

The free part that runs on the mac that you want to "extend" the display of is available as the "host software" at http://getairdisplay.com/

After I installed and rebooted and adjusted the installed System Preference panel (detailed directions and screenshots are part way down about "ON THE PRIMARY COMPUTER" at http://avatron.com/forums/read.php?47,15501 ) and then rebooted again, things are better on my headless MacMini ML Server, but not completely resolved. Any idea what settings need to be set?




Install a third party display driver (for example from http://getairdisplay.com) and it works!

 

[fhall1]

Good find indeed on the macminicolo site Did you happen to read post 20 in this thread?

The rest of your info is good though...

 

[mayuka]

I came across this posting: http://blog.macminicolo.net/post/33839671756/build-a-dummy-dongle-for-a-headless-mac-mini

I noticed that I need 3 resistors (85 Ohm) instead of just one. Putting them into the RGB ports (1-6, 2-7, 3-8) works on my 2005 Mac mini G4 and on my 2007 Mac mini C2D.

 

[j-beda]

spoke too soon

After I installed and rebooted and adjusted the installed System Preference panel (detailed directions and screenshots are part way down about "ON THE PRIMARY COMPUTER" at http://avatron.com/forums/read.php?47,15501 ) and then rebooted again, things are better on my headless MacMini ML Server, but not completely resolved. Any idea what settings need to be set?

I may have spoken too soon. After doing some screen sharing with a locally connected MacBook, the comparison shows the MacMini is still terrible, even with the Avatron software. Maybe the improvements thought I saw were just wishful thinking.

This discussion might also be of interest: https://discussions.apple.com/message/22657346#22657346

It gives a link to showing how to make a dongle with the 3 resistors mentioned above: http://www.geeks3d.com/20091230/vga-hack-how-to-make-a-vga-dummy-plug/

 

[idlememe]

Sorry to bring this up again, but has anyone tried this with one of the Mavericks developer previews? Does anyone know if the issue has been resolved?

 

[clie2k]

This appears to be fixed for me after upgrading my headless Mac mini to Mavericks.

I can do screen sharing via my MacBook Air and no longer get screen refresh issues or black box issues.

Can anyone else confirm?

After I upgraded the Mini, I tested screen sharing via the MBA before (Mountain Lion) and after upgrading the MBA itself to Mavericks, and it worked in both scenarios.

It appears if you just upgrade the Mini to Mavericks, any OS X variant can screen share with out the cursor/black box issues.

 

[krom]

Maverick

It's only partially fixed. Yes, the black blocks are gone but there's still a horrible refresh rate. It's really annoying that there's no patch for this.

 

[justanole]

The dongle solution works great

It seems that when you don't have a monitor connected, the GPU doesn't give you full performance. You can hack a dongle to make the mini think you have a monitor connected.

Image

Here's a full writeup by MacStadium on how to maximize video performance for a headless mac mini.

And cheap. The 100 ohm resistors are $1.49 a five pack from the Shack. The after market Mac adapter was $8 from Amazon. All in all a very easy and affordable fix.

 

[808?]

It gives a link to showing how to make a dongle with the 3 resistors mentioned above: http://www.geeks3d.com/20091230/vga-hack-how-to-make-a-vga-dummy-plug/

I made one of these today.

And cheap. The 100 ohm resistors are $1.49 a five pack from the Shack. The after market Mac adapter was $8 from Amazon. All in all a very easy and affordable fix.

Indeed, very cheap and cheerful.