Hi, so I recently began having this problem where when I plug in my laptop, I get an error message saying Adapter not recognized, performance may be affected, and my laptop is then very slow. It says it is plugged in but not charging. I already went into the BIOS and the adapter type said unknown. I then tried doing a Bios driver update but it did not fix it. The Led on the adapter still lights up as usual and I am using the same 130 W adapter as always. The weirdest thing is, in certain power outlets, sometimes do not get this problem and my laptop charges fine, but in others, it does not work. (I even got different results in two different plug holes in the same wall outlet.)
First thing to try is a new OEM Dell adapter. If that doesn't solve the problem, the next suspect is the DC jack in the system - one or the other is usually the cause.