I have one of the new mac mini's and run multiple users on it. At any time up to 5 users may be logged in. I have a keyboard and monitor that I connect to alot of machines so very often the mini has no monitor plugged in. When I connect my monitor – Dell Monitor, VGA to HDMI adapter that came with mini – I get just a plain blue screen. It looks like the blue that you see when the mac is switching users.
I've turned off all the energy saver options thinking that it might be going to sleep and not awaking. Any other ideas as to what might be causing this and how I can prevent it? Every time I connect my monitor I need to reboot to use the mini.
Update: I've tried a couple of more things – I turned off the screen saver also, I tried connecting to the machine using LogMeIn (http://logmein.com) all with similar results. It's as if when a monitor is not attached the mac stops outputting display. It is still running, I just can't get the display to work.
Update – this what I get when I SSH in and do a top command:
Macintosh-5:~ litmus$ top
Processes: 134 total, 2 running, 132 sleeping, 590 threads 10:39:24
Load Avg: 0.48, 0.46, 0.24 CPU usage: 1.87% user, 4.22% sys, 93.89% idle
SharedLibs: 4872K resident, 11M data, 0B linkedit.
MemRegions: 15034 total, 760M resident, 47M private, 228M shared.
PhysMem: 411M wired, 787M active, 382M inactive, 1580M used, 467M free.
VM: 335G vsize, 1042M framework vsize, 41811(0) pageins, 0(0) pageouts.
Networks: packets: 17481/3381K in, 18709/11M out.
Disks: 20134/790M read, 4894/76M written.
PID COMMAND %CPU TIME #TH #WQ #POR #MREG RPRVT RSHRD RSIZE VPRVT
547 top 6.4 00:00.26 1/1 0 24 43 1064K+ 264K 1640K+ 19M
538 SyncServer 0.0 00:00.12 5 3 42 87 1328K+ 5452K- 5988K 16M-
537 PubSubAgent 0.0 00:00.03 4 2 58 65 1528K+ 1412K- 3356K 33M+
521 SyncServer 0.0 00:00.13 3 1 39 83 1268K+ 5440K- 5924K 15M-
520 PubSubAgent 0.0 00:00.04 4 2 55- 65 1532K+ 1400K- 3384K 33M+
513 bash 0.0 00:00.02 1 0 17 24 256K 244K 920K 17M
512 sshd 0.0 00:00.05 1 0 11 68 284K 2492K 728K 584K
506 sshd 0.0 00:00.13 2 1 37 68 492K 2492K 4720K 796K
500 cupsd 0.0 00:00.06 3 1 48 68 1344K 328K 2916K 41M
497- LMIPSUser 0.0 00:00.03 9 0 44 55 452K 248K 1240K 31M
484 CCacheServer 0.0 00:00.00 2 2 35 53 604K+ 320K- 1648K 33M+
483 AppleVNCServ 0.0 00:00.01 4 1 46 56 884K 276K 3708K 31M
478 Litmus Test 0.7 00:01.61 10 3 148 118 47M+ 6116K 51M+ 77M
477- LogMeInGUI 0.0 00:00.09 4 1 84 82 1168K 5544K 3832K 31M
Best Answer
Finally figured this out. The issue had to do with the fact that I am using multiple users and Fast User Switching.
You can read more details about it in this thread: http://discussions.apple.com/thread.jspa?threadID=2177922&start=15&tstart=0
The gist is that each user has it's own loginwindow process running. These multiple loginwindow process' reek havoc with any method of remote controlling the mac -VNC, Apple Remote Desktop, LogMeIn even unplugging/plugging in a monitor is affected.
So you need to kill all loginwindow processes before connecting.
To do this:
ps auxwww|grep loginwindow
to find the current loginwindow processes that are running - there will be one for each user + one for consolesudo kill -9 pid
where pid is the process id* note: you do not need to kill the loginwindow for console
Much thanks to Martin Marconcini who led me down the path of investigating the running processes via SSH.