maybe boot again from the usb stick and ask boot-repair to repair. It should write grub to the proper partition. Reboot (without the sda), if you still get the white screen, I suggest clean reinstall.
maybe boot again from the usb stick and ask boot-repair to repair. It should write grub to the proper partition. Reboot (without the sda), if you still get the white screen, I suggest clean reinstall.