laptop lcd screen goes black

I have a Toshiba Satellite laptop model 1805 S204. Yesterday the screen started to flicker badly for a few minutes and then it was fine. Today when I turned the laptop on the screen lasted just long enough for me to log in and then went black. I could faintly see the desktop but not well enough to shut down.

If I close the lid or push the little button that the lid hits when closing, the screen comes back up, but only momentarily. I assumed that the light behind the screen was going and was ready to take it into the shop for service. But all of a sudden it is fine again. It has been up for about 4 hours with no problems at all.

In retrospect it seems as if there was a loose connection somewhere that was jostled back into position. The laptop has had no "accidents" such as rough treatment like slaming the lid or dropping. What can I surmize from this incident?