Windows – Dell U2414H monitor not recognized as supporting MST (Daisy chaining DisplayLink)

amd radeondisplayportmultiple-monitorswindows 7

I have two Dell U2414H monitors, and I'm trying to use multi-stream transport to daisy-chain the second monitor from the first monitor. According to the manual, this is supported. I've also followed the instructions here.

So what I've got is…

The packaged (not 3rd party) DisplayPort cable going from the AMD Radeon HD 7470 (which supports 'Up to 4 displays supported with DisplayPort 1.2 Multi-Stream Transport') and in to the miniDP on the monitor, then DP from the 'display out' port in to the miniDP on the second monitor.

I basically followed the diagram from the manual, but used miniDP 'in' instead of DP:

enter image description here
Yes, I did the power cables too 😉

Windows will not detect the second screen. It's stuck duplicating the screens, and there's no option to extend because Windows is not aware of the device.

Catalyst says the monitor does not support MST:

Screenie of Catalyst -- No MST

I've also installed the monitor's drivers (wasn't sure if that would help). Both screens are set to use DisplayPort 1.2 (and we've disconnected/reconnected cables after changing settings). Not sure where to go from here.

Could the miniDP be throwing things off, or is something else at play?

Best Answer

One thing you can check is that you cables are okay. Lots of cables do not follow the standard. Pin 20 (power) is the pin near the / side of the connector. It should be disabled for passive cables. Only active display port adapters can draw power from it. Check with a multimeter if pin 20 of the cable is disabled. My problems went away after I opened up one end of the connector of the cable and disabled pin 20, I cut the yellow wire of the cable.

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