|The laptop can't detect "the charger" - it can only detect whether the battery is being charged by the AC (to DC) adapter, indicated by a specific led lighting up on the laptop when it is being charged. It's normal for that led to cycle on and off, unless the laptop was running for a while on the battery alone, in which case the led will light up for a longer time when you connect the AC adapter again.|
If you unplug the AC adapter then plug it in again, the "charging" led should at least briefly light up at first no matter whether the battery is fully charged or not.
(That "charging" led DOES NOT light up on an Acer laptop I have when the battery is removed and I have the AC adapter plugged in. That led DOES light up even when the computer is NOT running when the battery is installed and the AC adapter is plugged in, if the battery needs charging.)
If that led never lights up, or rarely lights up, you have a problem.
The most likely causes are
- the wiring near the plug on the AC adapter cord that plugs into the laptop is damaged, or the plug itself is damaged
- the jack in the laptop is damaged - it should not be loose in the laptop
Those things are caused by the user frequently pulling on the cord when unplugging the AC adapter from the laptop instead of pulling on the plug on the end of the cord.
If you wiggle the cord near the plug, or wiggle the plug in the jack, the led may go on and off.
It's quite rare for the AC adapter to fail, unless the cord has been damaged such that it's shorted.