Windows not detecting display port

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Jul 21, 2014
Hello all,

I am trying to connect a monitor to my laptop via display port. I am using a display port to hdmi adapter. Windows 7 is not recognizing it where as it works fine with ubuntu on the same laptop. I have tried restarting my computer, re-installing my graphics drivers but no luck.

Laptop specs:
Hp Probook 6465b
Processor: AMD A6-3410MX APU with Radeon(tm) HD Graphics
Graphics card: AMD Radeon HD 6520G
Windows 7 Professional
Ram: 8gb

Any help will be appreciated.



Nov 29, 2012
1. Do you have a tv with an hdmi? Try hooking it up to the tv. Make sure after connecting it, you reboot though.

2. Some laptops require a function + (random key) to enable their secondary outputs. (saves power) So maybe your dp is not enabled.

3. I don't know. bad adapter???

4. I like using numbers as bullet points.


Jul 21, 2014

Why won't the adapter work with windows OS? If it is working with linux then it should work with windows as well. Am I missing somthing here?
When you connect a cable of a digital nature it does more than you think.
From windows to the video card when you plug the host device into it.
It does two things.
When you use Hdmi or the display port.

The monitor or client device is requested to give the graphics card its resolution table and the amount of Hz each resolution runs at.
Windows makes a note of this then sets the according value table sending it to the graphics card driver to the ramdac
To program all the values of information it revived from the client Device.

If this fails to happen it has no reference or Information.
So a image is not synced but out of range most of the time to high in Hz.
When you switch from say a laptop screen to a large TV.
The native resolution must be there, or received from the client device.

Now sometimes that hand shake is not done if the tv is already on due to driver switching.
It happens on old models of large LCD TV`s or Plasma's.

Common display port set resolutions.
Now if your lcd screen on the monitor is set to any other than value in the list below. and the Hz range.
You will be met with a black screen. They are set display port resolutions that should be sent from the client device.

1280 × 720 × 24 bpp @ 60 Hz 1.79 1.54 1.78
1920 × 1080 × 24 bpp @ 60 Hz 4.15 3.33 3.56
1920 × 1200 × 30 bpp @ 60 Hz 5.81 4.62 -
2560 × 1600 × 30 bpp @ 60 Hz 10.46 8.06 -
3840 × 2160 × 30 bpp @ 60 Hz 21.39 16.00 -

The other thing to watch out for is the two types of adapters Passive, and None passive.
With one you can reach a top resolution with a high quality DP cable.
Where as the other will only produce in the table about 1080p max because it is limited by the bandwidth of the cable used and the type of adapter.
You have to check if the DP works at a resolution, with a passive adapter or None passive.
depending on the OS and the driver.

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