A few days ago my first string computer died abruptly, and I bought from a local shop a Lenovo Think Centre tower with a 120 G SSD and 4 G of RAM without an operating system. They installed my old hard-drive and I took it home to play with.

Before doing anything else I went online using a live CD of Puppy Linux Xenial to deal with messages, which seemed to load and run very quickly.

I installed Linux Mint 19 Cinnamon to the SSD without difficulty and then downloaded updates, and then installed Chromium, Brasero, Grisbi, and Gnucash; the tweaks were all drawn from

https://sites.google.com/site/easyli...cinnamon-first

These were all things I have done with my last installations without any problems resulting.

By that time I suppose I had started the computer half-a-dozen times without any difficulty. Each time upon starting the computer showed Mint 19 as the first option and Mint 18.3 as a second option, but always started Mint 19 from the SSD without hesitation.

last evening the computer simply came up to a black screen with a blinking cursor. Shutting down and restarting gave the same result.
I then tried with the disk of Puppy Linux Xenial which worked, although it seemed much slower loading than the first time.
When Puppy opened I was surprised to see it was showing two partitions for the SSD, although when I installed Linux Mint, I had treated the SSD as one partition and had set its flag to boot.
Puppy was showing sda1 as 1 Mib, without a file system, and sda2 as 111.79 Gib in the ext 4 file system.

Looking at them with Gparted, sda1 had a flag set for bios_grub, and sda2 did not have the boot flag set. I left sda1 alone and set the boot flag on sda2 and attempted to restart, but just returned to a blank screen.

I then tried the live usb of Mint 19 again, and was disconcerted to find that it ran very badly: Firefox would not open, nor LibreOffice, and the shut-down menu was missing.
I tried again with a live flash-drive of Xenial which was much faster than the CD I had been using.

So, does anyone have any ideas of what went wrong, or where that 1 Mib partition came from?

I could simply try a reinstallation, but if I do I might try an earlier version of Mint—and I would prefer to have some idea of what went wrong the first time!

I did notice on visiting the Linux Mint home page a known issue concerning
Swap with home directory encryption, which I wish I had noticed before.

Guessing the 1mb partition (as you mentioned is bios_grub) and you have a hybrid system (bios that supports gpt partitions). The boot flag is, I believe, no longer necessary on these systems anyway. I have a hybrid system and always have to create a small bios_boot/bios_grub, partition when I do an install.

But that doesn't solve your issue...what type of video card in this machine? Just asking because cinnamon runs in 2 modes: full on 3d hardware rendering or "software" mode, which is horrifically slow. Maybe an update killed the 3d video driver? Does running live with puppy work (no black screen) and is it fairly snappy?

Upon running lspci I had this:
VGA compatible controller: Intel Corporation Xeon E3-1200 v3/4th Gen Core Processor Integrated Graphics Controller (rev 06)

Running the live flash-drive of Puppy is very quick; I am almost certain that the live CD of Puppy is much slower than when I ran it before.

Many thanks for your comments.

OK - that puppy seems slower is subjective so we can't quantify that really. I have zero experience with performance of the integrated graphics controller on Xeon chips so don't know what driver, etc, they require, other than it's going to be Intel.

So, Mint Cinnamon requires 3d acceleration to work, period, otherwise it runs in software mode. Are the appropriate 3d drivers installed in your Mint system? If not, that explains the horrible performance. If you can get to the Mint desktop, there is a "hardware driver" menu or set up option but since I haven't used Mint in a very long time, I can't advise as to where it is exactly. That menu option/item will install the appropriate 3d drivers for you. This is all assuming the graphics controller has 3d capabilities of course...if it does not, time to switch to another Mint desktop like xfce4, which runs very fast and does not require 3d acceleration.

Hope that is at least somewhat helpful...!

The Mint installation went from running beautifully (the first half-dozen times I started it) to refusing to start at all.
I find it hard to see it being a hardware issue.
If necessary I will download Mint again (perhaps an older version?) place it on a different flash-drive, and reformat the SSD.

Odd - except maybe something got updated that killed it? At a loss - you would think if no changes, the system performance would remain stable.

I have downloaded Mint 19 Cinnamon again, verified the SHA, and the computer started happily. I was prepared to reinstall the system, but was taken aback when I saw that the live flash-drive was only recognizing the HDD. Going to the Computer folder, I see ADATA SU650, which I believe is the SSD, but it will not mount.
I am going to think about this for a bit, but given that Puppy includes GParted, and does see the SSD, I will (after lunch) run Puppy, try to reformat the SSD, and try again with Mint.

Interesting - any chance the ssd is going bad or maybe the cable is bad? Motherboard drive controller maybe? Brainstorming...

Using GParted in Puppy, I reformatted the SSD to ext4 and set the boot-flag. I then shutdown and started with the Mint 19 flash-drive, and came up to a black screen with a blinking cursor again. . .so I haven't exactly improved the situation.

I shutdown and restarted with the Puppy flash-drive (and was very relieved that I was able to do so) but saw nothing wrong.

I tried again with Mint, and while I was pondering what to do, the screen came up offering to boot the Mint 18.3 installation that is on my HDD, and that ran. ADATA SU650 still turns up in the Computer file, and still refuses to mount.

I am still slow to see it as a hardware problem, given that Puppy consistently sees the SSD, but what did I do that stopped the Mint flash-drive from booting up?

Are you using mbr or gpt partition tables? The boot flag is not necessary if your system supports gpt partition tables. Not sure if that is causing an issue.

I am using gpt.

Just for the hell of it, I reopened GParted, removed the bootflag from sda1, shutdown, and tried again with the Mint 19 flash-drive — and it booted up quite happily.
Although I usually like having my mind stretched, mine is beginning to feel a bit spongy. . .

I will try a reinstallation.

Boot flag is not needed on gpt partitions - I haven't set the boot flag on a linux install in probably 10 years, lol.

Glad you got it working!

The installation is done. I have installed Chromium, Brasero, Gnucash, and Grisbi. All the other tweaks that I rushed through I am going to take at a slower pace. And I'll wait a bit before I call this solved--i don't want to tempt fate!

And. . .something is wonky.
The computer started three or four times without difficulty.
Then, this afternoon,it came up to a black screen and hung there until I turned it off.
When I restarted it, it booted up quite happily.

When it starts,it shows the Lenovo symbol for a moment, then a black screen for a moment, and then the bootscreen for a moment, offering the choice of Mint 19 on the SSD or Mint 18.3 on the HDD.
This evening it hung again: I was watching carefully: it showed the Lenovo symbol for twenty seconds (at a guess) and then stayed on the black screen until I turned it off. When I tried again it started happily.

The only constructive thought that occurs to me is to wonder if, if it were the SSD that is defective,I would have thought it would try the HDD, not simply hang. Also it has always started in Puppy.
I was interested to see another thread on this forum referring to troubles shutting down and restarting--I guess I will read through that next.
Any ideas?

I guess it is inconsistently wonky: on my first try this morning, it showed the Lenovo symbol for a moment, and then went to a black screen and apparently did nothing for several minutes. I was called away, and returning to the office several minutes later, and found that it had booted up Mint 18.3 from the HDD.

I decided to go with it, and started a download of Mint 18.3 (thinking that attempting to reinstall an older version might be the next thing to try). Returning to the office an hour later (I have a slow connection) I found the computer had locked up: the panel was there, but blank, and though it showed my desktop icons, when I clicked on one a window opened declaring it an unknown file, without a program to open it.

After shutting down, the computer restarted quite happily in Mint 19 from the SSD.
I am going to try again to download Mint 18.3.
Until now I have doubted this was a hardware problem, but at the next opportunity I will run Puppy for a day--although it has always run, possibly it has simply been luckier than Mint at playing Russian roulette with an erratic problem.