problem is DP only?

[hardwareaddicts]

I am running a nice system with a GTX 980 and everything worked fine, I have 2 screens - one is an old 4:3 monitor, and the other is a G2460P by AOC, a 144hz 1080p. 

I was running my 4:3 monitor with a DVI cable (since it dont have HDMI) and my AOC with a DP (for 144hz)
last week my AOC monitor started stuttering until it just wont turn on anymore, so I got a new one (more like QA tested used one) under my warranty, but now when I plug in my DP, the only resolutions available to me are 1280x960 or 640x480.
I plugged it in every single DP connection on my GTX980 and all gave the same results, however plugging in a HDMI works fine but it only runs 60hz like that, and since I only have 1 DVI output on my GPU, I cant run both screens on like that (and I dont have a VGA on my MB or card, so thats gone too) 

could that be a problem with the screen? seems weird to get another failed one that had a QA assurance sticker on it.. and Im afraid that my GPU might be dying?

[Gungpae]

Sounds like a bad generic display port cable. Try buying a new display port cable

[hardwareaddicts]

I forgot to mention but I did! I bought a new cable and its the same problem

[sazrocks]

Try forcing the resolution/ refresh rate using a custom resolution.

[Glenwing]

A lot of problems with improper detection of resolutions can be solved by forcing the monitor to reset, so it will go through the handshake procedure again. Which basically means, try unplugging the monitor from power for a minute.

[hardwareaddicts]

Tried forcing custom resolution and unplugging the monitor for few minutes, none of them work.. starting to think maybe its my GPU (altho its weird that 3 DP outputs are doing the same thing?)