Hello everyone,
First post here.....

I have been running Kubuntu 20.10 for a year or so on my Samsung Ultra book.

When installing, I partitioned the HDD and installed Kubuntu in a small directory and the rest of the drive I used for my files.

Lately the laptop has been warning me that I was low on space in my home directory.
I tried to remove some unused apps, Delete files etc, but the warning kept coming back so I installed BleachBit.
I cleaned a bit at the time, trying to get more space, but suddenly Kubuntu said I had 0 space left and it frooze.
I had to hard 'Power off' but then have not been able to get back into it.

Starting it normally brings the log-in screen, but then it freezes there.

Booting from the live USB brings two errors:

1. Failed to start Ubuntu live CD installer and
2. Failed to start Simple Desktop Display Manager

Pressing Esc on booting brings the Grub menu, I get a long list of possible commands, I tried a few, but nothing happens.

I am writing from my tablet, I took some screen shots of the laptop, but I am not able to upload, possibly because I am new on the forum...

Can anyone help me with some advice?

Many thanks

I may be wrong, but I don't think there's any "minimum posts" requirement to attach files to posts, though there is a maximum to the number of total attachments you can have. To attach pictures to posts, you have to click the "Go Advanced" button beneath the compose/edit window; then you will see the attachment dialogs.

You might try booting to a Live CD/USB or something, mounting the partitions on your hard drive, and checking disk usages with it, paying especial attention to /home. You could also take the opportunity to back up any crucial data to external media just in case this turns out to be the worst case scenario, as the saying goes.

The OP states that a liveUSB generates errors on boot - might imply the boot actually fails, but that is not stated explicitly.

Looking at that list of problems I'd say the device itself has failed. We had a similar situation with a ASUS ultrabook some years ago. I couldn't get it to work, and my better half wanted some mail I hadn't yet backed up, so I opened it up. Had a mSATA SSD (note this is before m.2 and NVMe). Had a proprietary interface so I had to get a special cable from China, but was able to get the data off. The machine itself was beyond redemption.

I hope you have better luck, but if you can't successfully boot a liveUSB, I can't offer anything concrete.

I inherited my Samsung from someone who through it across the room in frustration and smashed the display. I can't install Linux on it because of default UEFI firmware settings. I know this guy knows nothing of computer settings and has never tampered with them.
I cannot boot a optical disk, USB etc. I put Linux images on the drive that should boot but won't etc.

If the OP was able to install Linux means UEFI firmware settings have been altered to accommodate installation. It's possible there is UEFI settings out of whack or it's a Samsung thing. It's possible mine was producing the same errors while trying to boot a Linux install DVD, for lack of a display that works in POST I don't know.

To sum it up, I can't boot anything other than Windows on the drive with my Samsung. It had Windows 8.1, I had to install Windows 10 in VMWare and put it in OOBE mode, take a .wim image of it, inject the proprietary Intel graphics drivers, apply the image to the Samsung drive and it took about 6-8 minutes to set itself up before the Welcome screen finally showed up on an attached monitor.

Check UEFI settings

You should have memtest option in grub menu, try running it.

Thank you all for taking the time to read this and answering.

I will try to get a new live USB from someone and try it.
I do have a small SSD and I installed Kubuntu there.
Memtest return error: not found....

Today I can attach files, probably someone enabled the function or one needs to make 1 post first...??
Please see attachments.

Attached Thumbnails

       

OK, there's a few different things going on here.
That failure of the liveUSB might be a bad USB - let's hope so. Else it might indicate a memory error or somesuch, which might explain all your problems The memtest mentioned above is a stand-alone program that is sometimes included by distros and added to the grub boot menu. It is not a grub sub-command, which is why it failed for you.

See how you go with a different USB. Maybe Brains will be able to offer a better suggestion.

I have a sneaky suspicion I might be able to get something to happen with a wired keyboard on my end. (Since I could make out changes in the display in the pieces that had light of some kind)

Seams I was able to get the boot menu blind, but nothing seem to happen once there. I worked on an Acer that forced me to use Ubuntu's onscreen keyboard in a live session as nothing matched the key I would strike on the physical keyboard, all kinds of weird characters and letters, just not the right letter.

This Samsung might have the same disease, you never know.

So,
I had a friend lend me a Windows laptop, I tried to create a new USB live on my old USB stick, but could't, so I threw it into the garbage bin.
I burned a new live disk on a new USB stick and it all worked OK.
The new Kubuntu install is on a partition and all my old files are intact in a second partition.
I could not be happier, now I just need to re-install a few programs, but all my data files are available.