i have recently bought a HP pavillion 15 notebook. it was working fine untill i noticed a problem with its LCD.
whenever i set the brightness to minimun it changes automatically. whereas i set the brightness to max it doesnt changes.
i have disabled the ambient light sensors as well just to see if that was interfering with screen brightness but no use.
then i updated the BIOS and ran diagnostics and everything was ok.
waiting for ur suggestions people