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Consistently connecting to an external monitor
February 22, 2013 8:25 AM   Subscribe

Is there a correct sequence for turning on, and plugging in, my MacBook Air, to make it play nicely with a generic HP external display?

My Setup: 2011 MacBook Air, with an HP L1910 external monitor, connected via the thunderbolt port with a mini-dvi to VGA adapter. I like the external display as an extension of the MacBook screen, not a mirror.

The Problem: When I plug the mini-dvi adapter in, the MacBook display fades blue and fades back again as it changes screen resolution, but the external display does not consistently "turn on". I end up in a frustrating roundabout of unplugging and replugging the mini-dvi adapter, repeatedly hitting "Detect Displays", trying to adjust the screen resolution, and turning the external display on and off. Some or all of these things are usually eventually effective, but I am not clear what it is that eventually makes the external display spring to life.

The Question: Is this a screen resolution problem, or something about the sequence of switching on / unsleeping the laptop or the display, or related to the timing of plugging in the connector? Or are these connections just flaky?
posted by roofus to Computers & Internet (5 answers total)
 
I have almost the exact same setup (with a Dell Monitor and 2012 MBA) and my sequence is to have both the monitor and the laptop turned on and "awake" before I connect them.

But I don't really have this problem even when I vary that, and what you describe sounds more like a buggy adaptor or other hardware issue.
posted by pete_22 at 8:31 AM on February 22, 2013


It does sound like you've got a hardware issue with your adapter, but Mac laptops will attempt to operate in "clamshell mode" if they are (a) connected to a power source and (b) connected to an external monitor while closed. That may be tripping you up, so I agree with pete_22's advice to plug in and wake up your Mac before connecting it to a monitor.
posted by mkultra at 10:00 AM on February 22, 2013


This sounds very much like a hardware issue - the macbook is having trouble finding the monitor. Cheap things to try include making sure the connection of the cable is snug in the monitor, and making sure the adapter is snug in the cable (unplugging and replugging is the usual way). Next steps are finding alternate pieces of equipment for each step in the chain, and seeing which one fixes the issue. (My first guess would be the adapter, those things are super flaky).
posted by contrarian at 10:20 AM on February 22, 2013


My current setup is an MBA (late 2012) plugged into a Dell external monitor, but I like to use it in mirrored mode with the laptop lid closed (clamshell mode, as above).

My daily sequence: unpack laptop, attach the power adapter (buying an extra one to live on my desk was a great move), plug in DVI, plug in USB connector to keyboard/mouse, plug in audio-out, mutter under my breath about when the HELL will all this be integrated into one connector, and click my mouse / tap the keyboard.

The Air usually takes a second or two to wake from sleep, connect to the display, render, and return control to me.

So I don't think your Mac needs to be awake when connecting. I think the issue is more likely to do with a flaky connector, or a flaky monitor input. Either way, a hardware issue - it shouldn't be causing problems. I've used my setup across two laptops now for over 3 years, and never had a problem.
posted by RedOrGreen at 11:33 AM on February 22, 2013


I have a similar problem with a Dell monitor that does not consistently come out of sleep mode when I connect my Mac laptop to it. After much experimentation and frustration, I eventually discovered the following: on the occasions when the problem occurs, after connecting the monitor to the mac, if I leave the monitor connected and put the Mac into sleep mode deliberately (hit the Mac's power switch followed by a key press to the letter 's'), then wake it, the monitor wakes up and senses the Mac normally.

This sequence may not work for you, but might be worth a try?
posted by StrawberryPie at 1:00 PM on June 1, 2013


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