Answer to "Audio cutting out when applying pressure onto keyboard surface."I just finished diagnosing an X555 with the same issue. The problem was with the connection between the motherboard and the HDD/Audio daughterboard. When pressure is applied to the top of the case, it would flex and cause some pins to stop making contact (I noticed the power/status lights would not work when pressure was applied either). This is not a great design choice by ASUS and I hope to fix the machine by replacing the screws that were missing from the rear of the case which should make it more rigid and reduce the amount of flex.