Second display cannot be detected

[Graemephil]

I recently purchased an LG Flatron monitor to use as my second display for my MacBook Pro (unibody). I had it working with great results for about a week, but today when i plugged it in, the monitor is not detected. I have been looking through other's problems trying many of the same things, to no avail. Any other advice would be very much appreciated.

This was the only other one i saw that was a problem similar to mine, though time seemed to have solved the problem:
https://forums.macrumors.com/threads/271099/

 

[Repo]

Troubleshooting tips:
1) Make sure the external monitor is set on the correct input
2) Restart Macbook with and without external monitor connected
3) Turn external monitor on/off while connected

 

[Graemephil]

Tried all of these several times, but nothing. All of the cords i'm using have been used for less than a week. When i plug in and unplug the MiniDisplay my Pro's screen will go blue for about a second, so it's sensing some sort of change.