Forgot about this until the power went out again earlier & l lost more work
The solution is simple, create an application shortcut in the keyboard settings to run the xrandr command that enables the notebook's monitor.
What I found was when using monitors of 2 different resolutions, if the larger external display is used as the primary & xrandr is used to start the disabled smaller one, the smaller one will try to display at the same resolution as the primary/larger one, in my case I had 1280x1024 as the primary & the smaller one is 1024x600.
When the smaller one was started I found the panel was off the screen, couldn't be used etc.
I know there are parameters for resolution etc. that can be used in the xrandr commands but I couldn't make them work, instead I found that disabling the signal being sent to the larger monitor made the smaller one display correctly.
To find what displays are connected on the system open Terminal, type in
xrandr and hit Enter.
You should get something appearing that looks similar to this:
home@debian:~$ xrandr
Screen 0: minimum 320 x 200, current 1280 x 1024, maximum 4096 x 4096
LVDS1 connected (normal left inverted right x axis y axis)
1024x600 60.00 +
800x600 60.32 56.25
640x480 59.94
VGA1 connected 1280x1024+0+0 (normal left inverted right x axis y axis) 337mm x 270mm
1280x1024 60.02*+ 75.02
1280x960 60.00
1152x864 75.00
1024x768 75.08 70.07 60.00
832x624 74.55
800x600 72.19 75.00 60.32 56.25
640x480 75.00 72.81 66.67 60.00
720x400 70.08
On my setup LVDS1 is the smaller notebook monitor, while VGA1 is the larger external monitor.
The command for the application shortcut to enable the notebook's monitor using xrandr is:
xrandr --output LVDS1 --auto
The command for the application shortcut to disable the signal to the larger external monitor is:
xrandr --output VGA1 --off
To run both of those in one action from the Terminal it's:
xrandr --output LVDS1 --auto && xrandr --output VGA1 --off
Unfortunately that single command doesn't work with the application shortcuts (if it does I couldn't figure out how), 2 seperate entries have to be created.
One using
xrandr --output LVDS1 --auto to enable the notebook's monitor and the 2nd,
xrandr --output VGA1 --off to disable the signal to the external monitor.