Looking For Alienware 14 old model Laptop Charger (ac) Need Help

I have an old model Alienware 14, (not the 14x). The only chargers I see listed on Amazon are for the 14x, so I was wondering if it would also be compatible with the older model of the 14. They seem to be the same specs, the only difference I see is part number on the charger itself. I tried calling Dell but they require a serial number and my Alienware 14 doesn't even have one on the bottom of it, so they couldn't help. I have found the right models of it but they are sketchy ebay links which I have tried in the past and never got delivered. 

Laptop - Alienware 14 (not 14x)

Charger -

Model : DA150PM100-00

Dell P/N: KFY89

REF. NO.: ADP-150RB D

INPUT: 100-240 V ~ 2.5A 50-60Hz

OUTPUT: 19.5V  7.7A

The Alienware 14x charger 150w on amazon has the same specs and looks identical but it doesnt say it's compatible with the p/n of the one I need/ have of KFY89

Any help would be greatly appreciated. (its been months)