Ubuntu OS not booting - includes Boot-Repair report

[jdias5]

I installed successfully, some years ago, a Ubuntu Desktop 22 LTS in a bootable SSD on a Intel i5 Desktop System. This system was only sometimes in usage.

Now, when I switch on my Desktop, the BIOS don't see the the SSD, only the CDROM. However, if I boot the computer from an Installation CD of Ubuntu 22.04 LTS, I have access to the SSD, mounted in a ad-hoc location.

Also, I phoned the montherboard manufacturer, that said to me that if the SSD isn't shown, the problem would be probably that the boot partition was corrupted.

I ran Boot-Repair, and it produced the report in https://paste.ubuntu.com/p/vZpPvchhkX/

Thus, I am asking to the experts on Ubuntu what should be the repair procedure. Should I try with the recommended repair on the pastebin I indicated?

Thanks

[grahammechanical]

Now, when I switch on my Desktop, the BIOS don't see the the SSD, only the CDROM

What does that mean?

a) When you boot the computer you get an error message saying no operating system found.

or

b) When you enter the BIOS/UEFI settings utility and open the boot manager section the SSD is not listed.

In the BIOS/UEFI boot manager section is the SSD enabled/activated?

Regards

[oldfred]

You have an UEFI system.
You have grub installed in MBR for old BIOS boot and grub in the ESP - efi system partition for UEFI boot.
And you have the very old MBR(msdos) partitioning. Ubuntu allows this with UEFI, but probably should not.
The only time MBR is required is for older systems that boot Windows in BIOS mode.
Microsoft requires gpt partitioning with UEFI boot.

You do not show an ubuntu entry in UEFI boot menu. starting at line 51.
It looks like Boot-Repair is suggesting the full reinstall of grub in UEFI boot mode, which would add an entry in UEFI to boot Ubuntu.

Make sure UEFI system settings have UEFI as default boot mode.
And always choose to boot USB flash drives in UEFI boot mode.

Would be better to eventually convert to gpt, but MBR to gpt totally erases entire hard drive, so good backups required or starting over when you get new drive.

[jdias5]

1. When I access BIOS, the CDROM is listed, but the SSD is not listed.
2. When I boot the computer without a CDROM in it, the system doesn't boot. Says something like: "Insert a boot device and press a key..."
3. The computer was assembled in 2019, with recent hardware.
4. In BIOS, the 6 SATA 6G are set to be discoverable, but not hot-pluggable. As I said, only the CDROM lists here, as in the boot menu of BIOS

Thanks

[oldfred]

When you say UEFI/BIOS are you referting to boot menu or system settings?
System must show drive as Boot-Repair report shows it.
And Ubuntu entry is missing from UEFI boot menu.

Make sure UEFI settings are set to UEFI only.
If you try to boot in old BIOS mode, the grub in MBR will not work.

[jdias5]

I have changed the BIOS settings, enabling "UEFI only" for "Launch CSM\Boot Device Control" and "Launch CSM\Boot from Storage Devices".

However, the BIOS presents the same problem: the SSD is not listed, and only the CDROM is listed.

Note: now if no CDROM is inserted, the system opens the BIOS window.

Should I go for the Boot-Repair recomendation?

Thanks

[tea for one]

Should I go for the Boot-Repair recomendation?

Do you have a backup of your personal data?

[jdias5]

Yes I think, but I would not like to reformat the disk to start an installation from scratch.

In fact, my system worked well until some weeks (months?) ago.

[tea for one]

Starting from scratch would, actually, be a sound idea.
You could then format your disk with GPT and install in UEFI mode - a modern approach.

Anyway, if you are reluctant to do this, let boot-repair do its magic.
You have a backup, which is the most important ingredient.

[jdias5]

I have tried the Boot-Repair recommendation. The report is in https://paste.ubuntu.com/p/z5pYfP7nFH/

However, after setting to UEFI only the whole CSM menu: Boot from Storage Device, Boot from Network, etc., neither the computer boot from the SSD, nor, after accessing the BIOS, detects the SSD at all. When I access the SATA 6G list of devices, only the CDROM is there, not the SSD.

Thanks