secondary screen only works until login

[Colin Law]

On 29 August 2017 at 21:11, Dave Stevens <geek at uniserve.com> wrote:
> On Tue, 29 Aug 2017 21:53:11 +0200
> Xen <list at xenhideout.nl> wrote:
>
>> Dave Stevens schreef op 29-08-2017 20:57:
>> > Hi,
>> >
>> > I'm using 16.04 on a Toshiba laptop. I want to use a secondary
>> > display, a Samsung SyncMaster 712n. I have it connected to the
>> > Toshiba's external VGA port. The display powered up and showed
>> > system activity right up until the automatic user login took place.
>> > I had the system configured to log me in without asking for a
>> > password. When the login took place the secondary display went
>> > blank. The system control panel shows an unknown secondary display.
>> >
>> > In an attempt to see where the problem lies I made a new (second)
>> > user with a password and required a credential check at login. When
>> > I log in as the new user the secondary screen mirrors the main
>> > laptop screen and continues to work until I logout then log back in
>> > as the previous (admin) user, then it blanks.
>> >
>> > I suppose if I knew more about the graphic setup this would tell me
>> > where to look for more info but I don't.
>> >
>> > Anyone have a suggestion about where to look?
>>
>> Yes always just look at xrandr I guess.
>>
>> xrandr is a tool you can use to make those changes.
>>
>> Of course rather tiring to have to use it by hand.
>>
>> xrandr -q will list all connected (and unconnected) displays in your
>> system.
>>
>> xrandr --output DVI-I-1 --primary --output HDMI-I-1 --clone
>>
>> for example should, if DVI-I-1 exists, make that the primary display,
>> and I think this would copy that screen to the HDMI-I-1 if it exists.
>>
>> So the syntax is basically first --output NAME and then --something
>> to affect it.
>>
>> You can also set resolution with --display 1440x900 or something and
>> --scale 1.4x1.0 or something, or --scale-from 1440x900 or something.
>>
>> --auto will do auto configuration.
>>
>> If you figure out how to do it you can create a desktop shortcut to
>> do it etc.
>>
>> Good luck.
>>
>
> ooh! ooh! you da man! got it, and easy too. Thanks!

Oh well, more than one way to skin the proverbial cat I suppose.

Colin