charging issues with dell laptops

hello all,

i have witnessed such an issue on many dell laptops that, with age, the charger which was originally shipped with the dell laptop does not charges the laptop. even though it is able to supply power, but there is no charging at all. the laptop (bios) does not recognizes the charger as the original one. however, the laptop (charger) works very well with another dell charger (laptop) with successful charging.

i do not understand where the issue lies? in the charger, or in the laptop SMPS.

please provide an elaborate explanation, if possible.

thank you.