HDMI output

Hello,

I have BBB and waveshare 7 inch 1024x600 connected via HDMI and usb (touchscreen) plug on power and everything is ok.

When I change screen to DELL P2314T I have problem. If I disconnect HDMI plug power on and wait around 1 min until BBB loading and after that connect HDMI cable - everything in ok, but if I didnot disconnect HDMI result - black screen

How to fix it?

`

root@beaglebone:/# uname -a
Linux beaglebone 3.8.13-xenomai-r78 #1 Sat Sep 26 16:54:43 UTC 2015 armv7l GNU/Linux
root@beaglebone:/#

`

`

root@beaglebone:/# cat /proc/version
Linux version 3.8.13-xenomai-r78 (root@a6-imx6q-wandboard-2gb) (gcc version 4.6.3 (Debian 4.6.3-14) ) #1 Sat Sep 26 16:54:43 UTC 2015
root@beaglebone:/#

`

I try two different configuration for xorg

`

root@beaglebone:/# cat /etc/X11/xorg.conf
Section “Module”
Load “extmod”
Load “dbe”
Load “glx”
Load “freetype”
Load “type1”
Load “record”
Load “dri”
EndSection

Section “Monitor” $
Identifier “Builtin Default Monitor”
HorizSync 31.5-75
VertRefresh 60
EndSection

Section “Device”
Identifier “Builtin Default fbdev Device 0”
Driver “fbdev”
EndSection

Section “Screen”
Identifier “Builtin Default fbdev Screen 0”
Device “Builtin Default fbdev Device 0”
Monitor “Builtin Default Monitor”
DefaultDepth 24
SubSection “Display”
Depth 24
Modes “1024x768_60.00”
EndSubSection
EndSection

Section “ServerLayout”
Identifier “Builtin Default Layout”
Screen “Builtin Default fbdev Screen 0”
EndSection
root@beaglebone:/#

`

and

`

root@beaglebone:/# cat /etc/X11/xorg.conf.default
Section “Monitor”
Identifier “Builtin Default Monitor”
EndSection

Section “Device”
Identifier “Builtin Default fbdev Device 0”
Driver “fbdev”
EndSection

Section “Screen”
Identifier “Builtin Default fbdev Screen 0”
Device “Builtin Default fbdev Device 0”
Monitor “Builtin Default Monitor”
DefaultDepth 16
EndSection

Section “ServerLayout”
Identifier “Builtin Default Layout”
Screen “Builtin Default fbdev Screen 0”
EndSection
root@beaglebone:/#

`

but problem still same

How to fix it?