Am I right in assuming that my MBP will switch off power to the Mini Displayport, when running on batteries ? Well mine does, but want to make sure that's right ?
My does run a second display while on battery - 17" MBP from 2009 with 9400M. If you still have warranty you should have Apple take a look at it.
it won't turn it off after unplugging, but it won't start if your MBP isn't plugged in to start with.
Okay, I just tested it again and I run on battery, unplugged the monitor and plugged it back in and it took a bit longer (two to four and a half seconds) to actually recognise the monitor compared to when running the MBP on AC, but right now I run a second monitor while on battery. Btw, I use a MDP to VGA adapter, if that is worth anything.
From: Apple Portables: How to use your computer in closed clamshell (display closed) mode with an external display
Erm ... I don't see anything in the OP to suggest that he is talking about closed clamshell. cheers, Henry ____ Read the message carefully before you post
It'll work on battery but will drain substantially more energy. I don't think it's normal that it switches off, but I haven't tried with 10.6.5 yet.
Sorry, GGJ is right. I am trying to use it in a closed clamshell setup, so I can run the battery down, while using it how I do, day-to-day.
And we were supposed to know that ... how? The ol' rule still applies: the more information you provide, the better advice we can give. cheers, Henry
In all fairness, I would expect it to provide power to the Mini Displayport, when the lid is closed, otherwise you can't use any screen at all. I would have mentioned, if I'd thought it was pertinent. I was hoping is was a MD fault, as I'm getting crap HDMI performance ( http://forums.macrumors.com/showthread.php?t=1048660 ) , which might have accounted for it.
I use my 15" i5 on battery most nights running video on a 42" HDTV using mini displayport to HDMI and it always works fine. It does seem to use a lot more power though (understandably I suppose).