My computer doesn't work properly when plugged in

Have you ever tied to change the power settings?

First open the power settings, then click "change plan settings" beside the "balanced (recommended)" option. Then click "change advanced power settings" on the screen that appears. In the dialog box, scroll down and expand "Multimedia settings". Change the "plugged in" option to balanced.

Otherwise try to change the power states of the cpu, and see if it works.

You can also just check out the top 10 reasons for a lagging computer.

Hi,

What is the full model number of the laptop?

Have you checked that the voltage from the charger is a steady 19.5V at the charger’s output plug?

If Win 10 is installed create a Win 10 battery report to check the status of the battery. I realize that you said that it works OK when on battery power only, but power problems can be caused by a lot of things and they may have to be eliminated one by one. In this case maybe the battery actually faulty and is demanding too much power from the charger to the detriment of the rest of the hardware, whereas when it is on its' own it only supplies power to the laptop and there is no power from the charger.

Try starting the laptop in safe mode and check if the problem is there when the charger is connected to the laptop. If not then it is a driver problem, as in safe mode only basic generic Windows drivers are installed and not hardware specific drivers. The screen will look different because of this but it should still work as a laptop and you have to check if the problem is still there or not.

These are just tests to eliminate things trying to narrow down the cause of the problem.