Second monitor is blank
 

Installed lubuntu 18.04 i386 to an older laptop that was running windows 10 and I am greatly impressed with it's new lease on life! Only real issue I have is I'm unable to get the external monitor working. Xrandr shows both LVDS (primary) and VGA-0 connected.
~$ xrandr
Screen 0: minimum 320 x 200, current 2480 x 1050, maximum 8192 x 8192
VGA-0 connected 800x600+1680+0 (normal left inverted right x axis y axis) 376 x 301mm
1280x1024 60.02 + 75.02
1152x864 75.00
1024x768 75.03 60.00
800x600 75.00* 60.32
640x480 75.00 59.94
720x400 70.08
LVDS connected primary 1680x1050+0+0 (normal left inverted right x axis y axis) 331mm x 207mm
1680x1050 60.00*+
1400x1050 60.00
1280x1024 59.95
1440x900 59.99
1280x960 59.99
1280x854 59.95
1280x800 59.96
1280x720 59.97
1152x768 59.95
1024x768 59.95
800x600 59.96
848x480 59.94
720x480 59.94
640x480 59.94
S-video disconnected (normal left inverted right x axis y axis)

The graphics card is a ATI Mobility Radeon x1400 (RV515 chipset) and there are no errors in the /var/log/xorg.0.log file. lshw -c identifies the VGA controller as RV515/M54 and the driver as "radeon".
~$ lshw -c video
description: VGA compatible controller
product: RV515/M54 [Mobility Radeon X1400]
vendor: Advanced Micro Devices, Inc. [AMD/ATI]
physical id: 0
bus info: pci@0000:01:00.0
version: 00
width: 32 bits
clock: 33MHz
capabilities: vga_controller bus_master cap_list rom
configuration: driver=radeon latency=0
resources: irq:16 memory:d0000000-dfffffff ioport:ee00(size=256) memory:efdf0000-efdfffff memory:c0000-dffff

I am able to drag windows across to the VGA screen but can't see them (all blank). The VGA menu screen says it's in Power Save mode which I think means it is getting no signal. The VGA screen and monitor work when plugged into a different lubuntu laptop and I've closely inspected the cable connections. I'm thinking that maybe the video card is kaput! Any help is appreciated.

Check the manual for your laptop. Most of the laptops I've used have had a function key as a hardware control to switch to and from second monitors. It usually has an icon (intended) to represent a picture of display.

Thanks frankbell, the laptop does have a F8 function key toggle. Not the problem - it makes no difference.

There may be an error that isn't labeled as such in Xorg.0.log. Please share a complete Xorg.0.log and output fromThat external display running at 800x600 smells like it may not be using the Radeon Xorg driver, and even if it is, IME that generation of Radeon is rather quirky and may need some config help.

Something to try: switch from the desktop to a vtty (e.g. Ctrl-Alt-F3), then back (Alt-Fn, n being whichever vtty Ubuntu 18.04's X is running on, probably 1, 7 or 8). Does doing this product an audible snap, or two, or light up the external display, either for the vtty and/or for X?

mrmazda,

If you would provide all I asked for I might have more to offer. Try adding the following to your kernel cmdline:using the e key at the grub menu. If it works, reconfigure /etc/default/grub to include it, and then rebuild grub.cfg. Alternatively, equivalence can be provided via xorg.conf*. e.g. /etc/X11/xorg.conf.d/50-monitor.conf
alone might be sufficient, by switching the external display VGA-0 to using the same refresh rate as LVDS, along with the external display's preferred mode instead of 800x600.

mrmazda, wrt contents of Xorg.0.log - it's too big a file for this thread to handle ie: > 30000 characters. Can I apply some filtering to produce a lesser size file?

Switching ttys from F8 and back tyo F7 did not result in any monitor changes.

I'll now try to implement your latest suggestions.

Thanks, Dave

explains how to upload Xorg.0.log so you can post a URL here to where it can be seen.

Switching to vtty3 (Ctrl-Alt-F3) should have produced a massive change, fullscreen text mode, instead of LXDE.

mrmazda, pastebinit didn't work for me, viz:

and yes, (Ctrl-Alt-F3) did put the monitor into full text mode.

I edited the ~/.bashrc for
which produced the following from xrandr aftyer a reboot
Hope this helps, Dave

Is the external display still black?

pastebinit isn't the only way to upload a log. Among others:
https://paste.ubuntu.com/
https://pastebin.com/
http://paste.debian.net/
http://susepaste.org/
https://paste.fedoraproject.org/

If you have Apache running you can host it yourself.

mrmazda, ok I used your first link. The created URL is https://paste.ubuntu.com/p/dH8FsCMZ6h/

and yes, the screen is still black

Cheers,

Dave

I don't have any laptops, much less one with RV515/M54 [Mobility Radeon X1400], but I did spend some time trying to get close with a PC, eventually coming up with:on 18.04 running TDE and IceWM desktops. The only significant difference between our two gfxchips is yours is specifically mobile. That means DVI-0 here instead of LVDS, but also my VGA-0 display works as expected.

IceWM only takes a few seconds to install and requires nominal disk space. Why not give it a try to rule out LXDE as your problem? Also your display manager could be related, which is what, LightDM? You could try another. I like TDE's TDM, a fork of KDM, very fast on older hardware, relatively lightweight yet well-featured, and very mature.

Another way to test is bypassing the display manager. Boot in text mode by appending a 3 to the cmdline in the Grub menu. When you reach a login prompt at the completion of boot, login and start a default X session using the startx command. To make it work you might need to either install xserver-xorg-legacy, and/or either login as root or to run startx as normal user first do as root or using sudo do:If none of above works, the only other thing I can suggest is asking the AMD/ATI driver developers for help via their mailing list: https://lists.x.org/mailman/listinfo/xorg-driver-ati

mrmazda, I'll implement your suggestions. My system DE is LXDE, the WM is 'openbox' and the display manager is LightDM.I've downloaded IceWM and made it the default WM (via LXSession configuration) in place of 'openbox' but it looks like both are now running simultaneously - at least there are now two panels and both are active. I'll work my way through it. Thanks for your assistance so far. Can you tell me how to get into the Grub menu - holding the Shift key during boot doesn't work.

e for "Edit" current selection when the Grub menu appears.