Same issue here. Bought a replacement hard drive for this laptop and it will not show the drive after the first time I booted the device to install windows. This is the third hard drive I have tried in this machine and each time it’s the same issue; works for a short period of time and then the drive stops being recognized by the system at all.
I have cleaned the connections, tried a reflow of the daughter-board which has the SATA connector (and the motherboard too). Then tied a new HDD… NOPE. Fails within 30 minutes of the install.
Bottom line is this is a very poorly constructed laptop with poorly engineered parts. This was supposed to be an easy refurb for a friend, and it’s just turned out to be a money pit.
I do not recommend the Asus R5XX model line, and will be going back to Toshiba.