Member Avatar for choudhs

I have got an dual monitor issue that has stumped everyone I have tried asking about so grateful for any new advice!

When I try hooking up 2 monitors to my video card (ATI Mobility Radeon 7500), both monitors display the same content. Instead of being an extension, the second monitor just duplicates what's on the first screen.

I've tried to change the display in the Setting tabs on the Display options but to no avail. The dual monitor icons are displayed and it does let me click on the second monitor icon and allows me to do both of the following :

Right-click and select "attached" to activate it
Or check the "Extend my Windows desktop onto this monitor"

However, after then clicking "Apply", and allowing the machine to accept the settings, the computer appears to be accepting the settings - but then just reverts back to duplicating the info from the first screen onto the second monitor.

When I bring up the Settings again to check what's happened the second monitor is again not active anymore. Even when I move the two monitor icons around, and then it ask me that it will activate the second monitor for me, and I reply yes, the problem still does not go away - and the settings revert back again.

I think the issue is that the computer thinks that both monitors are the same as when I press the Identify button both monitors are identified as "1".

I'm sure I am using the correct cable and connections, and a compatible graphics card - otherwise I would not be able to see the same info on both monitors - right ?!

Do I need to update my drivers ??!! Please somebody help!!!

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On this generation of ThinkPad + ATI Mobility 7500, the dock’s VGA jack is electrically the same analog pipeline as the laptop’s VGA. A passive VGA splitter also repeats that same signal. In both cases Windows only sees one external head, so pressing Identify shows 1 on both, and any attempt to Extend reverts to Clone. The second, truly independent head is the dock’s digital output. Also note the GPU has only two controllers total, so you can drive any two of: internal LCD, dock DVI, or VGA, but not all three at once.

If you are still stuck (or for the FireGL V3400 case where only one monitor appears), try this quick checklist:

  • Remove any Y-splitters; connect each monitor to its own output.
  • Power on both monitors, then boot; open the GPU control panel and disable Clone, then choose Extend.
  • On Win7/8, press Win+P and select Extend; confirm both displays enumerate in Screen Resolution.
  • Update to the OEM or AMD legacy driver for your exact card and OS; avoid the Microsoft Basic Display Adapter.
  • Test cables/ports: prefer digital on both; if using a DVI-to-VGA dongle, it must be on a DVI-I port that carries analog. Try swapping ports to find the analog-capable DVI.
  • If hardware limits you to two heads, add a USB (DisplayLink) adapter for a third screen.

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Member Avatar for caperjack

I have got an dual monitor issue that has stumped everyone I have tried asking about so grateful for any new advice!

When I try hooking up 2 monitors to my video card (ATI Mobility Radeon 7500), both monitors display the same content. Instead of being an extension, the second monitor just duplicates what's on the first screen.

I've tried to change the display in the Setting tabs on the Display options but to no avail. The dual monitor icons are displayed and it does let me click on the second monitor icon and allows me to do both of the following :

Right-click and select "attached" to activate it
Or check the "Extend my Windows desktop onto this monitor"

However, after then clicking "Apply", and allowing the machine to accept the settings, the computer appears to be accepting the settings - but then just reverts back to duplicating the info from the first screen onto the second monitor.

When I bring up the Settings again to check what's happened the second monitor is again not active anymore. Even when I move the two monitor icons around, and then it ask me that it will activate the second monitor for me, and I reply yes, the problem still does not go away - and the settings revert back again.

I think the issue is that the computer thinks that both monitors are the same as when I press the Identify button both monitors are identified as "1".

I'm sure I am using the correct cable and connections, and a compatible graphics card - otherwise I would not be able to see the same info on both monitors - right ?!

Do I need to update my drivers ??!! Please somebody help!!!

drive update might help ,what model video card do you have , you are connecting using 2 cables attached to the 2 outlets on the video card correct

Member Avatar for choudhs

drive update might help ,what model video card do you have , you are connecting using 2 cables attached to the 2 outlets on the video card correct

I have an ATI Mobility Radeon 7500 video card...at least I think that is the model of the card :D

I am actually connecting two monitors to an IBM T41 laptop through a docking station. Both of the cables are analouge VGA. One of them is connected directly to the laptop and the other into the docking station (which has one VGA connection port and one DVI connection port)

I have tried using a VGA splitter box - thus connecting both cables to the splitter box and then the splitter box to the one VGA connection port on the docking station - but the problem still persists.

Thus I am now maybe thinking that I need to connect both monitors directly into the docking station - thus connect one of them into the DVI port using a DVI cable ??

Member Avatar for caperjack

Thus I am now maybe thinking that I need to connect both monitors directly into the docking station - thus connect one of them into the DVI port using a DVI cable ??

that sounds more likely to be the way to do it !
I have never seen it tried or done this my self ,have had duel on a regular 2 port video card ,but not a laptop ,if you only have 2 vga cables you can buy an adapter to got from vga to dvi!

Member Avatar for choudhs

Thanks CarJack!

I have now plugged in the other monitor directly into the docking station using a DVI cable & issue is now sorted.

Is as we thought...one has to connect both monitors directly into two different ports - otherwise if you try to split one of the ports then the computer will only recognise both monitors as one....as both are essentially connected to the one port!

Thanks for all your help man

Member Avatar for caperjack

Thanks CarJack![ lol i havn't done any of that lately ]

Thanks for all your help man

Your welcome ,thought that was best way , good to here you got it working

Member Avatar for aaffeld

I just installed a ATI FireGL V3400 128MB DDR3 PCI Express Dual DVI Video Card in my new Gateway DX Series desk top PC in order to run two monitors. Both monitors display the same thing. If I go to Control Panel (Display)only one monitor is shown. This is a Win 8 computer running in Win 7. How can I fix this? Allen

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