Re: Problem with external monitor
This will probably show as a new thread, due to me correcting a
spelling error in the Subject field of the message.
On 08/10/2014, Joe <joe@jretrading.com> wrote:
> On Wed, 8 Oct 2014 15:23:55 +0800
> Bret Busby <bret.busby@gmail.com> wrote:
>
>> Hello.
>>
>> I have a 23" monitor, that I want to use with two of my laptop
>> computers (not at the same time).
>>
>> I have a 15" laptop, with an i3 CPU, running Debian 6 LTS and GNOME2.
>>
>> With the external monitor connected and switched on, upon bootup, the
>> external monitor is automatically operational, and, replaces the
>> laptop display.
>>
>> That is good.
>>
>> The other laptop has a 17" display and an i7CPU, and is running Debian
>> 7.x and LXDE.
>>
>> With that laptop, with the external monitor connected and switched on,
>> upon boot up and during a boot session, the external monitor does not
>> work, and, is apparently not visible to the computer. The laptop
>> display is operational, and no signal appears to be going from the
>> laptop. Synaptic shows lxrandr to be installed, but the exernal
>> monitor is not detected.
>>
>> In Preferences -> Monitors, only one monitor is shown; the laptop
>> display.
>>
>> I also tried logging in to a GNOME Classic session, but got the same
>> result.
>>
>> Both scenario's involve the use od a VGA cable and connection to the
>> VGA socket on each of the respective laptops. That it is using the
>> supplied VGA cable, and not aDVI or HDMI cable, is not a problem for
>> me, as I find the resolution to be good enough for me.
>>
>> How do I get the external monitor to be detected, and, work, with the
>> Debian7/LXDE system?
>>
>
> Something I would suggest you try soon is a different model of external
> monitor. If you spend weeks fiddling about with drivers and then find
> the VGA socket on this laptop simply doesn't work, you will feel
> foolish, trust me on this.
>
> Something else to try would be booting up a live CD of a more
> commercial kind, such as Ubuntu or preferably Knoppix, to find out:
> a) if it works
> b) if so, what drivers it is using
>
> Is the external monitor going into standby, by the way? I have an old
> laptop and know of someone else's monitor which simply doesn't work
> with it. The laptop VGA circuits want to see an active monitor
> connected before they will power up, and the monitor wants to see a
> live signal before it will come out of standby, or avoid going into
> standby from switch-on... I haven't found any combination of switch-on
> time and plugging that will actually allow them to work together,
> though I presume there is a window of a few microseconds when they
> would find each other. The laptop is fine with other monitors, the
> monitor with other laptops.
>
I have downloaded Ubuntu 14.04.1 LTS amd64 iso, and tried that.
One interesting observation, is that, with the 15" laptop running
Debian 6 LTS, on bootup, all video output goes to the external monitor
(and to only that monitor), and, with the 17" laptop running Debian 7
(and then Ubuntu 14.04.1 LTS), the ACER spalsh screen and the BIOS
screen, go toonly the laptop monitor.
That made me wonder whether either the BIOS or the graphics card,
could not deal with the external monitor.
However, with Unbuntu 14.04.1 LTS, which took 10-15 minutes (on an i7
CPU with 32GM RAM) to boot, the output started to appear on the
external monitor, after the weird double icon with the equal sign at
the bottom of the screen, so I got the Ubuntu word, with the simulated
LED flashing things (a fake progree bar) appearing on both screens.
At the end of the bootup, I have on the external monitor, a workspace
(?) with a panel/taskbar, and no icons on the desktop, and, on the
laptop display, I have a workspace with the dialogue box or window,
with the Welcome thing, with the options to select the languge, and to
select "Try Ubuntu" or "Install Ubuntu".
In selecting "Try Ubuntu", I get a desktop on each of the two screens;
the one on the external monitor does not have the two icons "Examples"
and "Install Ubuntu 14.04.1 LTS", whereas the display on the laptop
does include those two icons.
I can not find how to get the pointer off the laptop display and on to
the external monitor.
In selecting (on the laptop display), the System Settings -> Displays,
I get both monitors displayed.
When I select , for "Built In Display", "Off", the laptop display goes
off, for a short period, and all control goes to the external monitor,
and then the laptop display comes back on, with the pointer and the
"Launcher" (?)icons, all on the external monitor.
After shuuting down the live session of Ubuntu 14.04.1.LTS and then
booting up Debian 7, to find whether the booting into Ubuntu, had
flicked some switch that would enable displayiong on the external
monitor, in Debian 7, Ifound the system to be unchanged from the
previous advised problem - no external monitor detected.
In Debian 7.x, selecting (in LXDE) Preferences-> Monitor Settings,
which shows only the laptop display being detected, and the external
monitor not being detected, LXRandR shows as version number 0.1.2 .
Booting into Ubuntu again, in selecting System Settings -> System ->
Details -> Overview, the Graphics is shown as Intel Haswell (Mobile).
In System Settings -> Hardware -> Displays, both monitors are shown.
When I run lshw in Ubuntu, in
pci -> pci:0 -> display, it shows as "3D Controller", the GEForce GT750M,
and, in
pci -> display, it shows as "VGA compatible controller", "4th Gen Core
Processor Integrated Graphics Controller" ; "vendor; Intel
Corporation"
-I assume that to be the Haswell thing.
I do not know, in Ubuntu, how to get the software name and version
number, that is the equivalent of the "LXRandR version number 0.1.2
".
in the Debian lxterminal lshw output, for both pci:0 -> display, and
display (without the pci:0 ->)the first line, hence, for both the
nVidia and the Haswell controllers, the line states "UNCLAIMED". I do
not know whether that is of any significance;
"
*-pci:0
description: PCI bridge
product: Haswell PCI Express x16 Controller
vendor: Intel Corporation
physical id: 1
bus info: pci@0000:00:01.0
version: 06
width: 32 bits
clock: 33MHz
capabilities: pci normal_decode bus_master cap_list
configuration: driver=pcieport
resources: irq:40 ioport:4000(size=4096)
memory:d2000000-d2ffffff ioport:a0000000(size=536870912)
*-display UNCLAIMED
description: 3D controller
product: NVIDIA Corporation
vendor: NVIDIA Corporation
physical id: 0
bus info: pci@0000:01:00.0
version: a1
width: 64 bits
clock: 33MHz
capabilities: cap_list
configuration: latency=0
resources: memory:d2000000-d2ffffff
memory:a0000000-afffffff memory:b0000000-b1ffffff
ioport:4000(size=128) memory:b2000000-b207ffff
*-display UNCLAIMED
description: VGA compatible controller
product: Haswell Integrated Graphics Controller
vendor: Intel Corporation
physical id: 2
bus info: pci@0000:00:02.0
version: 06
width: 64 bits
clock: 33MHz
capabilities: vga_controller bus_master cap_list
configuration: latency=0
resources: memory:d3000000-d33fffff
memory:c0000000-cfffffff ioport:5000(size=64)
"
--
Bret Busby
Armadale
West Australia
..............
"So once you do know what the question actually is,
you'll know what the answer means."
- Deep Thought,
Chapter 28 of Book 1 of
"The Hitchhiker's Guide to the Galaxy:
A Trilogy In Four Parts",
written by Douglas Adams,
published by Pan Books, 1992
....................................................
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