output voltage for asus laptop charger gradually deacreases

[saidi.firas.6]

my asus laptop charger suddenly stops charging and when i tryed to mesure the output voltage it gives me at first 19v and start deacreasing gradually then the voltage suddenly rises to 25v and start decreasing again and it keep doing this in loops !!!

 

[1shado1]

Time for a new charger.