View Full Version : running 2 monitors (DVI to VGA)

Barrie G
01-07-2008, 07:54 AM

I'm newish to Macs so please bear with me ... (I have tried searching for similar articles but nothing matches exactly) here goes ...

I have a white MacBook (13.3") screen and want to use it with an 18" NEC MultiSync 1810x monitor (either mirrored or dual, pref dual). I bought a mini DVI to VGA convereter from Apple, plugged it into the DVI - VGA cable that is connected to the Multisync monitor, connected an external keyboard and mouse (per other posts) and crossed my fingers. Turned the monitor on, nothing there. Ran the 'detect monitors' in Screen Preferences, I see two screens, one called 'Monitor' the other called 'NEC Multisync'. Still nothing there. Other times when I connect the NEC, i get two screens displayed when I run Detect Monitors, but this time instead of the NEC being called NEC Multisync, it's now called 'Display'.

I then went through a trying changes to the screen resolutions for both screens, turning on and off mirroring, and somewhere along the way (I don't know how) got them to work in dual monitor mode - don't ask me how - that's the purpose of my post! When it worked, the second screen was described as 'Display' not 'NEC Multisync'.

When I first turn on the NEC Multisync, it comes up with a system message saying 'DVI signal detected', it aslo has underneath it 'Analog', I have tried selecting both but it make no difference.

The really annoying thing is I have had it working with dual monitors - anyone know what I should do our how the heck I did it? The NEC has great resolution which I'd like to use.

Any help greatly appreciated.


01-07-2008, 09:44 AM
Why are you using a DVI-VGA adapter? Doesn't the NEC 1810x have a DVI port as well? Ideally, your NEC should be used with one resolution and that's 1280 x 1024 (if running analog then 75Hz). Ideally, you should be using a Mini-DVI-DVI adapter to send the digital signal to the monitor rather than analog.

Barrie G
01-07-2008, 09:53 AM
I'm currently using it (DVI to VGA) because the NEC monitor is shared with a PC, and the monitor sharing port only has VGA. The NEC does indeed have a DVI port and I can buy a mini DVI to DVI cable adapter (and hopefully that will work with my Mac), but it means I can't use it with my old PC ...

01-07-2008, 02:31 PM
Some monitors can handle switching between two live inputs (one VGA and one DVI for example), but others cannot, and simply default to one signal or the other. Can the NEC handle two live inputs? Perhaps as a troubleshooting test, unplug the DVI cable completely from the NEC (not from your old PC). Does the NEC suddenly work with your MacBook? If so, then the NEC cannot handle multiple live inputs.


01-07-2008, 02:39 PM
I've had a few NEC monitors, and they never had a problem switching between sources.

The monitor though, has only one resolution. While it may be able to display a few lower resolutions through pixel-doubling and such, it will be most stable if set to 1280x1024, 75Hz. Does your Mac support that resolution? If not, you might try using SwitchResX (http://www.madrau.com/html/SRX/About.html).