Monitor suddenly only recognized as digital flat panel 640×480

displaymultiple-monitorsresolution

I daisy chained the following monitors with Display Port Cables:
Dell U2414H,
Dell U2415

Everything worked fine till I came back from a presentation with my laptop and pluged the DP cable back in.

The first monitor is still recognized as before. But the second one gets recognized as "Digital Flat Panel" with a max resolution of 640×480.
The device manager looks like this:

enter image description here

Uninstalling the Flat Panel dind't work. Any other ideas?

Best Answer

This is inelegant, but it works:

  1. Make sure Monitor #1 has DisplayPort 1.2 set as Enable.
    Monitor #2 should be set as Disable.

  2. Open Device Manager. Click Monitors. Click View and Show Hidden Devices.
    Uninstall the Digital Flat Panel (640x480 60Hz) device.
    Also uninstall any hidden (greyed out) devices.

  3. Disconnect Monitor 1 from computer.

  4. Reboot computer

  5. Unplug monitors and wait a few seconds

  6. Plug monitors back in to power

  7. Connect Monitor 1 to computer.

I've had this problem for years and have searched all over for an elegant solution. To my knowledge, none exists.

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