How boot from second hard drive when it listed in bios?

Question

The question very similar to this, but no the same :(

Description

1. A second storage device (SSD) was installed instead of the optical drive
2. There was a one really successful boot from it
3. BIOS from time to time loses my SSD

The problem

1. When Esc is pressed, the SSD can be selected as a drive to boot now, but not always
2. When F2 is pressed, the SSD does not appear on the boot menu where you can save the boot order forever. But it is listed on "Advanced/SATA Configuration" BIOS topic.
3. Some times the SSD can not be seen on both boot menus: The startup and the BIOS. In these moments, the bootable USB drive is not seen too.

So what can be wrong with that? OK, may be there is some problem with drive detection, but why second drive cannot be selected even when bios recognize it?

System

The notebook is an ASUS x551ca. The OS is Windows 10.

Answer 1

I am going to assume Esc opens your boot device selection menu and F2 opens your BIOS setup.

You need to do some diagnostics on the hardware level, and if you can't do it yourself, you must take the laptop to a repair center where this can be done.

1. Try switching the places of the original HDD that came with your laptop and this SSD. See what's the result. (Does the laptop recognize SSD? Does it fail to recognize the HDD?)
2. Check the connection between your SSD and the laptop. Make sure it is clean. If there is a wire connecting it to the laptop, try replacing the wire.
3. Try the SSD in another computer to see if the problem is with the SSD hardware. You may need to backup its contents before testing booting from it.

Doing the above should give you the knowledge as to what is the culprit here: The SSD, the connection or the laptop. Armed with this knowledge, you can plan your next move.