Well from the pic you posted I only seen two pins on the power connector, it looks like pin #1 and pin #2 are missing.
Unless they were broken off for some reason, I'd say this device was intended to be only powered by the 5 Volt rail from the PSU.
I would try looking for information off of the IC chips on this board, try googling the numbers you see in white lettering on top of the chips.
This might give you an idea what those chips were designed for and what this device is meant to do.
There most likely was a label stuck to the board, but it probably has since fallen off.
I am not sure what the flat square area is though, the one opposite the printed circuit side of the board.
Did you say it looks like a screen? like as in LCD video screen?
I have electronic data books related to all sorts of circuit board components including IC chips, if you can't find any info on those chip numbers, post them and I'll look them up for you.
Also one last request, can you post a pic of a side view of this device? preferably a side showing any sockets or at lease a view of where the connectors you had in your hand are coming out.
Edited by MrBruce1959, 10 March 2010 - 12:02 AM.