Reboot and select proper Boot Device Error

[jkeslar]

I didn't see any prior threads that are completely similar to my situation....

Running Win 10 and PC completely froze while using it - had to completely power down and attempt to restart.

On restart, received the "Reboot and select proper Boot Device..." error. Thought I had a failed hard drive, and replaced it with an old bootable drive that I knew worked - same error message.

Attempted to boot PC using bootable USB - same "Reboot and select..." error.

I confirmed that both drives and the bootable USB were indeed working properly by installing and booting on a secondary PC - both drives and USB stick worked in that secondary PC without issue.

Replaced motherboard battery, reseated memory, all cables - same error. BIOS settings looked fine, but I changed and changed back settings just to be sure. CPU, memory, and all drives all register as fine in the BIOS.

Only 2 things I didn't try was replace the SATA cable to that bootable drive or try a different SATA port, but didn't believe that to be a problem since I can't even boot using a USB drive.

Any help on further troubleshooting steps?

I'm afraid I either have a bad motherboard, CPU, or memory, and because these are older components (4+ years), I'll probably just replace completely if I have to replace either the mobo or CPU. I can't, however, find anything that suggests that bad mobo, cpu, or memory would cause this particular error.

 

[popatim]

During power on (have your bootable USB stick installed) you are presented with an option to select the boot device, press this F-key and then select the USB stick and see if that will boot up.

If that works then power down and install the HDD and try the same thing again.

If that works then enter the bios and see if you can now set the HDD as the primary boot device or first in the boot order and save and exiting will reboot the pc. I hoping it boots up for you now.

 

[jkeslar]

Thanks for the reply. It was really odd - boot order was absolutely fine, and I also got the same error when specifically selecting the USB using the f-key (F8) for me. Tried switching the BIOS between legacy and EFI - same thing. Nothing helped.

Reset the CMOS again for like the 4th time to no avail, and finally in a last ditch effort, decided to just take everything apart. Remove the GPU card, memory, CPU, cleaned every contact with electrical contact cleaner, used new thermal paste, put it all back together. I didn't expect that to do anything, but miraculously, it actually worked.

I'm back in business. Have built PCs and worked on PCs for many years and never had that happen.

 

[popatim]

That sure was an odd one! Grats on the fix.