I had my Alienware laptop fixed about 2-3 months ago and since then it has been acting up a little, whenever I turn it on, it gives me a message along the lines of "cant identify charger, battery may not charge", it says to insert a "dell 180w ac adapter" but I checked and that's the one I have, the battery says its constantly its at 0% charging, and the biggest issue, sometimes when I'm playing a game, the laptop turns off, randomly and without warning, I've avoided doing any tests/resets as I'm not well versed in this kind of stuff, and I'm scared I might break something

AS mentioned before, i had it fixed because a key on the keyboard had come off, they fixed it by taking off the keyboard section entirely as replacing it.

How can I fix this?