I had an issue when I installed Ubuntu Mate on my Acer 575G. Laptop seem to be stuck in a boot loop. Every time I power on the laptop, it gave me an error message for about a second saying "no bootloader found" and then restarted. So, I had to press down the power button to get out of the loop.
After that I found a solution from "it's foss" to fix this very issue. In his article he guessed that the secure boot could be the cause behind this problem. But I had already disabled it. However, I was managed to fix this issue by following these steps.
- Turn the power off.
- Power on the laptop while pressing F2 key quickly. (Your BIOS key)
- Get into BIOS settings.
- Enable secure boot if it's disabled. It's under the boot tab.
- Go to security tab.
- Choose "Select an UEFI file as trusted for executing" option.
- Select the HDD you installed UBUNTU or your distro.
- You will see shimx64.efi, grubx64.efi and MokManager.efi.
- Important one is shimx64.efi. Select it and press enter.
- In next screen type "Yes" or the description you want & select Yes option.
- Save your BIOS settings and exit.
Source : https://itsfoss.com/no-bootable-device-found-ubuntu/