Question Win 7 second monitor suddenly stopped working

Tbone68 · Jul 14, 2017

Hi,

My Company Laptop is running win 7 professional.

I have a docking station, which has the monitors plugged in.
Both monitors are VGA.
One is connected via a VGA to DVI adapter.

When I first installed the second monitor last year everything was ok. Then I think after a windows update, the second monitor isnt recognised. I have checked both monitors, cables and adapter on a different pc and everything is working OK.
I try to detect another monitor, but it only finds the monitor connected directly via VGA

I cannot roll back the upgrade cos my company wont allow it. Also, my Company IT support is not very good. Anyway I am in the field, so I cant just ask them to pop over for a look.

Can anyone suggest what has gone wrong and how I can fix this ?

All hardware is OK, I have confirmed this.

EndlessWaves · Jul 14, 2017

Two VGA outputs are unusual, I'm guessing this is a fairly old machine?

If you try the non-functioning monitor on it's own then does it work?

Tbone68 · Jul 14, 2017

Non functioning monitor on its own works, but not when I connect it with the DVI adapter.
If I connect it with the DVI adapter to another PC it works fine.
The only thng I cant check is the DVI port on the docking station.
This worked perfectly until a windows update so i doubt it is the hardware.

Thanks for the reply.

EndlessWaves · Jul 14, 2017

Tbone68 said:
Non functioning monitor on its own works, but not when I connect it with the DVI adapter.
If I connect it with the DVI adapter to another PC it works fine.
The only thng I cant check is the DVI port on the docking station.
This worked perfectly until a windows update so i doubt it is the hardware.

Thanks for the reply.

So it's a DVI to VGA adapter and not a VGA to DVI adapter? The direction matters (source to display) because the two function quite differently. (most) DVI ports will output a VGA signal so most DVI to VGA adapters just change the plug. The reverse isn't true, so a VGA to DVI adapter is actually converting the signal from one format to another.

As I say two VGA outputs is unusual these days so I'm wondering if your video driver has been updated to a version that doesn't support it. It might be worth going to the computer manufacturer's website and getting the latest video driver they provide.