Cruiser13's questions

Ubuntu 20.04.1 abruptly stopped recognizing USB devices on the machine my kids use. Have tried with a mouse, a game controller, and a USB stick on different ports without success, all work when plugged into a different machine.

The computer is a Lenovo Yoga 900-131SK.

I have tried making each of the following changes to /etc/default/grub, updating grub, and then rebooting, without success:

GRUB_CMDLINE_LINUX=""to GRUB_CMDLINE_LINUX="acpi=force irqpoll"
GRUB_CMDLINE_LINUX=""to GRUB_CMDLINE_LINUX="iommu=soft"
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash" to GRUB_CMDLINE_LINUX_DEFAULT="quiet splash usbcore.autosuspend=-1"

I also tried chmod 777 /media/ without succcess.

I've seen a number of suggestions to check the BIOS to see whether USB is disabled there, but BIOS has been inaccessible (nonexistent?) on this machine since well before the problem emerged. (That's a Windows issue, apparently -- I was trying to set this up to dual-boot.)

Several programs were installed prior to the problem appearing: ri-li, kgeography, and childsplay. I've uninstalled all of them and rebooted with no change in behavior.

Output of lsusb with USB mouse plugged in is:
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 003: ID 8087:0a2b Intel Corp.
Bus 001 Device 002: ID 0bda:57e1 Realtek Semiconductor Corp. Lenovo EasyCamera
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

That covers every suggestion I've been able to find. Any other ideas would be welcome.

Running this through an external DVD drive. Videos app says DVD source is required to play the file, but is not installed. Hitting play in VLC activates the disc (you can hear it start up in the drive) but nothing happens. I've installed Ubuntu Restricted Extras and libdvdread4 and libdvdcss.

I know varieties of this question have been asked before, but none of the answers I've tracked down are solving the issue.

Running Ubuntu 17.10. Installed Synaptic Package Manager through Terminal, but it won't open -- just asks for my password and then immediately closes. Ultimately I'm trying to use it to install Zotero 5.0, so alternative routes to that are also welcome. Downloading through Zotero website leaves me with a desktop configuration file that's functional but buried in several layers of folders, and attempting to do it through a web-based curl yielded nothing at all.

Attempted running synaptic-pkexec and it produced an error message: "No Protocol specified. Tried synaptic and it returned "Gtk-Message: GtkDialog mapped without a transient parent. This is discouraged. Segmentation fault (core dumped)"

I have a battery power issue that I'm trying to resolve. One proposed solution involves adding some boot arguments and then removing the battery, but I'm running into trouble on the first step. To add a boot argument, I'm running

gksudo gedit etc/default/grub

However, I get this response:

Error copying '/home/username/.Xauthority' to /tmp/libgksu-0n0AJS': No such file or directory

New to Ubuntu and not an advanced user.