2nd monitor will flash display for half a second when connected then go black

[pissybob]

I'm connecting a monitor to my laptop to extend the display, it used to work without issue but now it takes ages of fiddling around to sometimes work. Generally when connected the display will flash on for half a second before going black again. The monitor always shows as connected on the computer.
After fiddling around with unplugging and reconnecting cable, opening and closing laptop, adjusting resolutions and refresh rates back and forth I can get it to work sometimes, when it does work it will work perfectly all day until either the cable is removed or laptop turned off, then I have to go through the same process again.
I've tried different cables, I've connected using the VGA with an HDMI converter, but all the same result.

Any ideas?

 

[popatim]

When the external display won't work, press its Menu button. If it doesn't bring up the menu then there is a problem with the Display itself. Try shining a light into it and seeing if the images is there. If so the issue is with the backlight.