Question Lenovo Thinkpad L380 Slow down when charging

[FriedCow]

the laptop is thinkpad l380 yoga, i bought it second hand and it slow down when plugged in. when i play tekken 7 on battery cpu goes upto 3ghz, but while charging it only goes 0.4ghz sometimes 1ghz but it still below cpu baseclock. is it need hardware change or can i do something with the software? the wierd thing is so far it only slowdown in tekken 7

 

[FriedCow]

the laptop is thinkpad l380 yoga, i bought it second hand and it slow down when plugged in. when i play tekken 7 on battery cpu goes upto 3ghz, but while charging it only goes 0.4ghz sometimes 1ghz but it still below cpu baseclock. is it need hardware change or can i do something with the software? the wierd thing is so far it only slowdown in tekken 7

now it happen to all my games
someone say its about the ac adaptor or ac jack idk