View Full Version : Flaky MBP Mini DisplayPort Port

3rd October 2012, 04:47 PM
I have a late-2008 MacBook Pro (first of the Unibodies I believe) which has served me well. One thing I noticed a little while back was that the Mini DisplayPort port on the side seemed to not quite work. I didn't need to output to a monitor when I first noticed it so didn't bother looking further into it, assuming the cable I was using was dodgy.

I've tried again more recently with a different MiniDP to DP cable, and the same issue presents.
Essentially what happens is that when I plug a Mini DP cable into the laptop, the monitor doesn't show a picture most of the time. I will unplug and replug a few times and eventually it will work. The Mac detects a new monitor and adjusts display accordingly (the model of the monitor shows up in Displays) but nothing shows on the Monitor itself. Have tested this with a Dell U2711, a Dell U2311H, an old Samsung with MiniDP -> VGA adapter, and a Toshiba TV with the same adapter. Same thing happens regardless of which cable I use, or which monitor I plug it to.
Once I get it working it is mostly reliable (unless I bump the cable) but it's a pain having to muck around so much each time.

I've tried resetting the PRAM, am running latest updates to Mountain Lion (the issue was preset under Leopard, Snow Leopard and Lion as well though), and have no idea what I can do.

Any ideas?

3rd October 2012, 05:45 PM
Reset SMC?

3rd October 2012, 06:01 PM
Pretty sure I've done that as well, at least the 'remove battery and power, hold power button for 5 seconds and put everything back'. Have to admit I just found the Apple support page with all the steps that should be taken beforehand that I haven't tried, so I'll give those a whirl.

Looking at that support page (http://support.apple.com/kb/ht3964?viewlocale=it_it) it doesn't appear to be related to external displays (except Target Display mode anyway).
Will go through the *full* procedure and report back.