Alienware m17xr4 17.3 How do know HD or not.

Hello everyone,

My Alienware m17xr4 17.3 LCD cable is dead. I found 2 kinds of cables on the market one for HD Dell P/N: 2JD3N 02JD3N and one Dell P/N: GTDTJ, 0GTDTJ.
How can I tell which one I have?
And where can I find the Dell pin?
Screen Res. 1600x900

Regards and thank you