Headless Macmini - black screen and cursor

[tonty]

I have a Macmini running Mountain Lion and Logmein has stopped working. All I get is a black screen. Same with Apple Screen sharing.

The odd thing is that it was working until last week.

Have also tried Chicken VNC and I get a login screen, then it goes black aftger logging in.

I can SSH, and mount the drives with no issues.

 

[chrfr]

I have a Macmini running Mountain Lion and Logmein has stopped working. All I get is a black screen. Same with Apple Screen sharing.

The odd thing is that it was working until last week.

Have also tried Chicken VNC and I get a login screen, then it goes black aftger logging in.

I can SSH, and mount the drives with no issues.

http://blog.macminicolo.net/post/33839671756/build-a-dummy-dongle-for-a-headless-mac-mini

This would probably solve your problem. Also, set the display sleep in Energy Saver on the mini to "Never."

 

[tonty]

I've ordered the cable and resistor from eBay - worth a try.

I'm just baffled as to why it was working flawlessly until a few days ago.

 

[tonty]

Update

The cable didn't help, so I'm a bit stuck.

Here's a summary:

• Headless Macmini, 10.8.3
• Logmein and Screensharing both fail. After login, I just get a black screen with a mouse pointer.
• Chicken VNC renders the mac login screen, but after than I'm at the black screen.
• I can SSH and mount the drives with no problems.

Things I've tried:

• The modified dongle
• Repair permissions
• Via VPN
• Getting cross

Any suggestions gladly accepted.

 

[drsox]

The cable didn't help, so I'm a bit stuck.

Here's a summary:

• Headless Macmini, 10.8.3
• Logmein and Screensharing both fail. After login, I just get a black screen with a mouse pointer.
• Chicken VNC renders the mac login screen, but after than I'm at the black screen.
• I can SSH and mount the drives with no problems.

Things I've tried:

• The modified dongle
• Repair permissions
• Via VPN
• Getting cross

Any suggestions gladly accepted.

I tried this a year ago, and also failed. I was using VNC (best of the bunch, but not for this).
Two suggestions : 1. Get a cheap small monitor and keep it attached. 2. Do what I did and build a DIY server (try a hackintosh as the problem is a Mac H/W issue - you should also solve the WOL problem by doing this).

 

[tonty]

Adding a monitor is sort of my final option. I'm hoping there are few steps between here and there.

However, the fact that this was working up until last week is what's got me most intrigued. Last week I didn't need a monitor and now I do? That just doesn't make sense.

 

[drsox]

Adding a monitor is sort of my final option. I'm hoping there are few steps between here and there.

However, the fact that this was working up until last week is what's got me most intrigued. Last week I didn't need a monitor and now I do? That just doesn't make sense.

Yes, I agree. Mine worked for all of 6 hours and then crapped out. This was on Lion.

 

[mmomega]

Have you tried setting the background to change every minute?

This worked for me, it keeps the screen refreshing. Haven't had a complete "black-out" since.

 

[tonty]

Have you tried setting the background to change every minute?

This worked for me, it keeps the screen refreshing. Haven't had a complete "black-out" since.

What background do you mean?

 

[mmomega]

The desktop background

 

[geeji]

You did not say what is happening when you connect a real monitor.
I suppose you do have (had ?) one, since otherwise you would have had to set the screen sharing option blind.
I had similar problems with a headless Mac Mini, and solved them using Gefen HDMI Detective Plus.
But that adapter basically does something very similar to the hacked VGA dongle which did not work for you, so I would first check it is not something simpler, like a corrupted system.
Also, the fact that is was working before (for weeks ? months ? year ?) without any dongle is different from my case.

 

[justperry]

You did not say what is happening when you connect a real monitor.
I suppose you do have (had ?) one, since otherwise you would have had to set the screen sharing option blind.
I had similar problems with a headless Mac Mini, and solved them using Gefen HDMI Detective Plus.
But that adapter basically does something very similar to the hacked VGA dongle which did not work for you, so I would first check it is not something simpler, like a corrupted system.
Also, the fact that is was working before (for weeks ? months ? year ?) without any dongle is different from my case.

$129 Your joking right.

 

[tonty]

You did not say what is happening when you connect a real monitor.
I suppose you do have (had ?) one, since otherwise you would have had to set the screen sharing option blind.
I had similar problems with a headless Mac Mini, and solved them using Gefen HDMI Detective Plus.
But that adapter basically does something very similar to the hacked VGA dongle which did not work for you, so I would first check it is not something simpler, like a corrupted system.
Also, the fact that is was working before (for weeks ? months ? year ?) without any dongle is different from my case.

I only ever plugged a monitor in once when setting it up. Ever since (about 6 months), I've always used either Logmein or Desktop Sharing.

I tried remotely changing the desktop background - this didn't help.

I'm thinking of reinstalling the OS, but I'm not sure if this is possible via terminal.

FYI, I'm 4,00 miles from the Macmini, so my options are limited.

 

[stukdog]

The cable didn't help, so I'm a bit stuck.

Those dongles have solved the issue for a lot of customers. When you first connected, did the resolution reset to a really small resolution? That's how you know it took.

I'm not sure why it does this black out on some machines, and not others.

 

[geeji]

If your Mac Mini is powered on 24/24 7/7, that may explain why it worked and does not anymore : a power off + reboot, after an initial setup with a real monitor (which continued to work after you unplugged the monitor).
And yes, the Gefen HDMI Detective Plus is expensive, but it worked for me (and others).

 

[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?

I tested it via the MBA before (Mountain Lion) and after upgrading the MBA to Mavericks, and it worked in both scenarios.

 

[tonty]

I'm not planning on upgrading to Mavericks, but I did find a fix for this.

All I had to do was to ask my relatives to buy a monitor, plug it in once, and the issue was cleared. The annoying thing was that I had to buy one, so now the monitor is sat 4,000 miles from me unused.

 

[clie2k]

As soon as your Mini gets rebooted (eg. power failure etc), someone will need to attach and detach the monitor for you again - the fix you have is temporary, unfortunately.

The only non-Mavericks permanent solution is the Gefen HDMI Detective ($120 from Amazon), which coincidentally arrived at my door step same day Mavericks was released (doh) and now I need to return.

 

[tonty]

That's not what I found. I only had to plug it on once to clear the issue. The Macmini has been restarted lots of time since then.

 

[clie2k]

Interesting. What configuration or OS version you running? Sounds like you've been lucky or have a config that's preventing the issue.

As you can see from this thread and any other thread you Google on the topic, folks running Mountain Lion on a headless Mac mini, which was initially set up using a monitor and then disconnected from the monitor, who then for whatever reason rebooted the mini physically, suffer from the screen refresh issue on screen sharing.

The common profile is:

- running Mountain Lion
- set up using monitor and then disconnect monitor
- physical reboot occurs for whatever reason (someone switches the mini off on the machine itself)
- screen sharing with headless Mac mini produces screen refresh issues

Solutions are:
- DIY modded VGA dongle to fool the Mac mini into thinking its connected to a monitor
- Gefen HDMI detective
- and possibly... upgrading the mini to Mavericks

 

[tonty]

It's a late 2012 Macmini, i5 running 10.8.3.