I've stumpled upon a problem that I've found kind of tricky regardning the infamous displayport, and it's doing really weird shit...
I first got my Lenono Y27G screen together with this PC from the store and everything worked for a few months, but later DisplayPort #1 would only have a black screen. I simply moved my DP cable to port #2 and everything worked for a while, until same thing.
Right now I'm on port #3 with my display and I got myself a second cheap monitor today, plugged it in and to no surprise it didn't work, yet as-though, port 3 worked for this monitor too. But to my surprise, with y27g at port #3 and the new display in port #2 my computer recognizes both displays and their name, I can even access the events-log for the items. But while the computer recpgnizes the monitors in 1 and 2, the monitors themselves prompt [NO SIGNAL] when only plugged in to 1 and 2.
I did some testing with switching cable and what I can tell, the monitor realises when I've pulled the DP-Cable out of either 1, 2 or 3 on computer as it changes from [NO SIGNAL] to [CHECK CABLE CONNECTION]. I believe the graphics card or my computer has somehow gotten the DP-ports corrupt and are somehow not sending it's information out.
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Other information
I've been at DisplayPort Link Failure after monitor sleep? and though about cleansing the DISPLAY key in (Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\DISPLAY) but I'm not to experiences with the registry and what I can do with most keys.
Nvidia Control Panel and Windows settings is both set to enable the monitor and the computer even allows my mouse to "leave" the main monitor and wonder of to the void where the other should be.
Here's a DXDIAG for display and GPU: dxdiag.txt
Finally, here's a few images explaining how it looks like: imgur gallery
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EDIT
When accessing the device properties for Lenovo y27g (monitor) I see a message stating:
Device DISPLAY\LEN65BE\5&19c0d498&1&UID4354 could not be migrated.
Last Device Instance Id: DISPLAY\Default_Monitor\1&8713bca&0&UID0
I remembered seeing this lise somewhere else and checked my regedit again. And of course there's the same string at the key:
Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\DISPLAY\LEN65BE\5&19c0d498&1&UID4354
I do not know if this could be something related to the problem but there's 7 other similar strings in LEN65BE. The Philips version has 5 similar ones too.