Weird issue with multiple monitor set-up

[benji1987]

Hi, I wasn't sure where the best place for this was so took a guess.

I recently made the leap to having two monitors rather than one. I started with a Samsung syncmaster T200, and purchased two LG W2246's. My PC has a Radeon 6850.

My issue is that for some reason, having the Samsung and one LG plugged in works fine, but having the two LG's doesn't - Windows doesn't detect the second display. All three monitors work fine on their own, and each LG works alongside the Samsung. It isn't an issue with cabling as far as I can tell. I have two VGA to DVI adapters and both monitors work with both adapters and VGA cables.

Obviously, this isn't ideal as I currently have a shiny new monitor not doing anything so any suggestions would be great. Or if I missed any details out from this then I'll happily add any if someone can point them out.

Thanks in advance

 

[stormy13]

benji1987, welcome to the Seven Forums.

This is your problem right here,

I have two VGA to DVI adapters and both monitors work with both adapters and VGA cables.

Only one of the DVI ports on the card supports VGA via adapter, the other will be DVI only. Using a DVI cable (or 2) should fix it, and from what I can see those LG monitors have both DVI and VGA ports.

 

[benji1987]

Re:

Ah right, thanks... I assumed that there wasn't any limits or anything. Is there any way around it or am I up the proverbial creek with a £100ish monitor/paper-weight?

 

[bassfisher6522]

All you need is a DVI cable(s)...or here in the states the go for about $20 each and go up from there. To get all three monitors to work you'll need a display port-adapter. I ran into the same problem when I first made the leap to a dual monitor setup. Then I got to 2 DVI cables and all is good.

Digital Visual Interface - Wikipedia, the free encyclopedia

DVI-D Dual-Link

This connector contains 24 pins, arranged in three horizontal rows of eight pins. To the side of this grouping of 24 pins is a wide, flat pin called a ground bar. A dual-link interface provides two TMDS links, or groups of data "channels" that can carry more than 10 Gbps of digital video information. A dual-link cable is backwards-compatible with single-link applications. The majority of DVI applications will use this DVI-D dual-link cable connection.

DVI-D Single-Link

A single-link DVI connector has 18 pins. The male plug has them arranged in two groups of nine pins, with the flat ground bar off to one side. A single-link interface provides one TMDS link. This type of cabling is ideal for use with DVI to HDMI adapters

 

[benji1987]

Forgot to mention this in my last post, but my monitor only has the one VGA port, no DVI one, anthough it does call it a D-sub (Assume this is the same thing). So no easy fix with a DVI cable... I did try a backwards adapter (DVI to VGA into the monitor) but no joy.

Is the displayport an easy option to get working? I can only see the two DVI ports on the back of the card. (Sorry if I sound stupid but it has been a long time since I have had any complicated monitor connectors. All my previous ones have been nice and simple DVI inputs.

 

[stormy13]

The only way to get it to work is with a VGA-DVI converter, an adapter will never work. You have to remember that DVI is a digital signal and VGA (D-SUB) is analogue. Also the one DVI port on the video card that supports both is configured to use both, it isn't the adapter that configures the signal. Unfortunately most of the card manufacturers don't like to label the back plate on the cards like this,



and show which of the two ports supports both. A converter would likely end up costing as much as you paid for one of the monitors.

Using the display port as mentioned above is a possibility. No idea what is available where you are but something like this,

Newegg.com - Encore ENCA-DV DisplayPort to VGA Adapter

looks like it would work and doesn't cost much.

All things considering if you can it would be easier to return the new monitors for a pair that have DVI connections on them, than messing around trying to find the right converters/adapters.