I installed Ubuntu 17.04 from a USB on my Acer Spin 5 which came with Windows 10. I made the choice of removing Win10 because earlier when I Dual-booted Ubuntu and Windows 10 I was not able to boot into Ubuntu after a Windows update.
Now when I start my computer it says
Default boot device missing or boot failed. Insert recovery media and hit any key, Then select "boot manager" to choose a new boot device or to boot recovery media
If entering this I only get the choice of booting with Windows Boot Manager which takes me back to this screen again, I'm also able to use my live-USB with Ubuntu and either load into Ubuntu live or install directly, both this options brings me back to the "Default boot device..." after a reboot. I've also tried boot repair with the following commands
sudo add-apt-repository ppa:yannubuntu/boot-repair && sudo apt-get update
sudo apt-get install -y boot-repair && boot-repair
But now after reboot I get
Failed to open \EFI\Boot\grubx64.efi - Not found
Failed to load image \EFI\grubx64.efi: Not found
start_image() returned Not found
Failed to open "\EFI\BOOT\Microsoft\grubx64.efi - Not found
Failed to load image \EFI\Microsoft\BOOT\grubx64.efi Not found
start_image() returned Not found
How do I solve this problem with not being able to get into Ubuntu?
How do I know which partition is my main partition? Running
sudo fdisk -l
gives
Disk /dev/loop0: 1.5 GiB, 1553670144 bytes, 3034512 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk /dev/sda: 238.5 GiB, 256060514304 bytes, 500118192 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disklabel type: gpt
Disk identifier: F2E8B05E-6E0D-493F-9FF1-9F5D1195680B
Device Start End Sectors Size Type
/dev/sda1 2048 1050623 1048576 512M EFI System
/dev/sda2 1050624 500117503 499066880 238G Linux filesystem
Disk /dev/sdb: 3.7 GiB, 4002910208 bytes, 7818184 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x1b571474
Device Boot Start End Sectors Size Id Type
/dev/sdb1 * 0 3142655 3142656 1.5G 0 Empty
/dev/sdb2 3118960 3123567 4608 2.3M ef EFI (FAT-12/16/32)