Another 22.04 problem, reboot fails, have to power cycle

[Liam Proven]

On Mon, 1 Aug 2022 at 22:59, Chris Green <cl at isbd.net> wrote:
> >
> All very well but I still fail to see why it worked perfectly with
> ubuntu versions from 19.10 through to 21.10 and only with 22.04 do I
> have this problem.

I've had analogous problems, way back.

Some time around Ubuntu 11 -> Ubuntu 12,  one of my 2 lovely big CRT
screens stopped working right.

They were a matched pair of 21" ones, Iiyama I think. Pretty old by
modern standards; they had separate R, G, B and sync connections on
BNC connectors as well as a VGA port each.

One continued as normal, the other would not reset to higher than
640*480, whatever I did.

Much troubleshooting followed. In the end I partly isolated it.

In the newer 'Buntu, X.org autodetected the screen capabilities from
the monitor. One screen was attached to a VGA port by a VGA to VGA
cable; the other using a VGA to 4xBNC cable.

Hang on... *searches*

Yes, found it in my history. I've posted the old message below my sig.

Long story short: monitor capabilities are passed, as data, over the
VGA port, using a system called EDID.

That can't be passed over BNC.

So, in that new version, it could no longer detect the monitor's
abilities, so suddenly it defaulted to the only thing that it "knew"
was safe. Basic VGA mode.

There was no fix. I had to switch cables to VGA-VGA. Then it could
read the screen's EDID data, and it Just Worked™.

>  To me it suggests that something in the Ubuntu
> boot sequence has been changed which is causing the problem.  The
> existing BIOS *can* work satisfactorily.

It could be. Or maybe some setting that wasn't read before now is, so
something is working that wasn't and stopping it booting.

"Improvements" can do that.

-- 
Liam Proven ~ Profile: https://about.me/liamproven
Email: lproven at cix.co.uk ~ gMail/gTalk/FB: lproven at gmail.com
Twitter/LinkedIn: lproven ~ Skype: liamproven
UK: (+44) 7939-087884 ~ Czech [+ WhatsApp/Telegram/Signal]: (+420) 702-829-053




---------- Forwarded message ---------
From: Liam Proven <lproven at gmail.com>
Date: Sun, 18 Nov 2012 at 22:39
Subject: Quantal - unable to set screen resolution
To: Ubuntu user technical support, not for general discussions
<ubuntu-users at lists.ubuntu.com>


I installed 12.10 on my machine tonight - happily, in a separate
partition, replacing my old 11.10 install and leaving 12.04 in place.

I say happily because it's not working very well.

Firstly, the nVidia drivers wouldn't work. Trying to change or remove
them without a window manager was... /challenging/ but fortunately I
could open a terminal with Ctrl-Alt-t, even though I had no menu bar
or launcher.

Some digging around on the command line suggested that
gnome-control-center might be the "system settings" control panel.
(Why not call it "control centre" if that's its name?)

Anyway, I ran that, went to Software Sources, tried all the 4 nVidia
drivers on offer - current, current-updates, 304 and 310 - none
worked. I went back to Nouveau but now that only gave me 640*480 and
no ability to change.

Using my Mac, I found this very useful page:
http://techhamlet.com/2012/11/install-nvidia-drivers-in-ubuntu-12-10/

This enabled me to remove and reinstall them in a working manner.

Now I have my main screen running at 1600*1200 again.

The snag is, my second screen, the right-hand one, is stuck at 640*480.

I can find no way to change this - nVidia-settings seems to think this
is all it can do.

I think I know why; the right-hand screen is connected with BNC plugs,
the left hand one with a VGA-VGA cable. This means no EDID data is
getting back to the graphics card.

However, that doesn't help me. It worked fine in 12.04 and 11.10!

Anyone got any ideas how to fix this?

I don't have a spare VGA-VGA cable, but I will see if I can get one
and swap over... that might help. BNC gives better image quality,
though.

-- 
Liam Proven ~ Profile: https://about.me/liamproven
Email: lproven at cix.co.uk ~ gMail/gTalk/FB: lproven at gmail.com
Twitter/LinkedIn: lproven ~ Skype: liamproven
UK: (+44) 7939-087884 ~ Czech [+ WhatsApp/Telegram/Signal]: (+420) 702-829-053