I have asus 5z after purchase mobile working good but 1st update it get problem. Wheneve I play sound it get automatically decrease . Also when I change into mono to stereo or stereo to mono sound decerease in 2sec... I checked in service center but they told change the speaker it changed but problem not solved.... Also I tell issue on mail but no one answers me. Right now my mobile is out of warranty so they charged me lot so didn't go again to service centre. Definitely I didn't buy asus mobile next time... Any one have same issue like me.