Strange boot issue installing KUbuntu

Question

So, I've installed Linux many times in the past, generally from a liveUSB, as I'm using now. It's a 32 GB SamData SD101, on USB 2.0. (Probably excessive for an installer, but it's what I had on hand and it was empty.)

I am currently running Linux Mint 20.4, and it's past time for an upgrade, so in this island between projects, I'm attempting to try KUbuntu on it. I download the iso for 22.04.3 and burn it to said drive with Mint's USB Image Writer app, plug it into a USB 2.0 port, and restart; then, I hit F11 for my boot device selector and choose the USB.

A moment later, I'm greeted with the basic installer options, specifically Try/Install KDE, etc., and I choose Try/Install. After that, the weirdness happens.

I get the power-on boot splash, as if it's stuck in POST. This is hard data on the motherboard, and after I select from the boot menu. There's a little LED blinking on the USB drive, but I've seen it go on like that, with the POST splash, for more than ten minutes. (Figured I would get some household chores done and come back to it, in case it's just taking a little while; but the mobo splash was still there.)

As far as I can tell, it's just stuck. On concluding this, I remove the drive from the USB 2.0 slot, and depress the power button to manually power-off my machine; then I wait at least twenty seconds (old habit to protect my HDD) and turn it on. Mint 20.3 boots normally. Current OS acts like nothing happened.

Aside from that initial GRUB-like menu, I never get the option to try or install KUbuntu. (Clearly I installed Mint on this machine some time ago, and do not know if I've dealt with this before... it's been a busy few years.) Just a hang on the splash screen, and a potentially irrelevant red light on the thumb drive, seemingly indefinitely.

I've got some ideas, but I do not know what I'm doing wrong, and need some advice.

Additional data: The motherboard is an MSI MPG x570 Tomahawk Wifi. None of the debug LEDs are informing me of an error with power, RAM, CPU, or detection of a disk; they're behaving normally, so I'm assuming it isn't the mobo. I very recently installed a 4 TB Crucial NVMe M.2 drive, which runs fine on my current OS and doesn't seem to be defective at all; it's been formatted and auto-mounts, and I've had no difficulty storing on it or reading from it (in fact it's KUbuntu's target disk, if it can ever get around to that part). My USB is plugged into an otherwise well-behaved USB 2.0 slot on the front of my machine, which I regularly use for writing to storage, though it is attached through the case and is not directly on the motherboard. Lastly, my graphics card installed is currently an RTX 3050, but that shouldn't matter to a LiveUSB, should it?

I recently installed the last LTS of KUbuntu onto an Ideapad without issue, so this is a little weird.

Thanks for any assist.

Answer 1

So, I got it on there. Here's what was happening.

To begin with, now that I've got some time for it, I cleared a USB port at the back of my machine and plugged the thumb drive in there. (It's not easy to get to, but doable; I usually just use that space for consistent peripherals and the front-panel or a hub for everything else.) This was part of the problem, but not all of it.

Turns out that the 32 GB thumb drive I'm using had two partitions burned onto it as part of the KUbuntu image, for some reason. Booting to one would get me the GRUB screen, then complain (for a flicker) about a lack of boot directories and then dump me at the boot splash. Interesting. I only recall one drive partition showing up when it was plugged into the front, but can't explain why this is different. Note that this was not the behavior where the KUbuntu logo shows up beneath the power-on splash, but just the power-on splash.

Booting to the other partition was where I hit my second weird issue. My CPU is a Ryzen without embedded graphics, and all attempts to boot were going through an RTX 3050 plugged in. Apparently the LiveUSB had a little trouble with that, and was dumping me on a blinking cursor screen for a very long time, possibly indefinitely. To be sure, I left, made lunch, ate it, and came back the better part of an hour later, and it was still there; apparently this is a known issue with Nvidia cards.

Powering off, and rebooting again, took me to the option of "safe graphics" mode, which couldn't hurt. This took a moment but brought me to Try/Install KUbuntu in very low resolution. After verifying that everything was functional, I installed onto my M.2.

Rebooting to it, everything is flawless. Since I opted to download proprietary material too, the Nvidia driver is already installed. System powers on and off in a practical blink of an eye. I still need to customize it to my liking, but all is well.

So, in summary, plug the USB drive in the back, be prepared for issues with an Nvidia card (minus a driver for it) and use "safe graphics" to get around them, and install proprietary material too if you've got a big media setup so the reboot will take full advantage. After that, all has been well.