What if you setup a way that it has 7 Leds and and the last wire is ground and have a pic with at lest 7 i/o or a 4 pin pic and a shift register and shift a 1 in all the line so it flashes down the list and on the other end make sure you set it up with a correct wire so the leds flash correctly. Ill make a schematic to better explain
This should work for a Cross-Over Cable. If connections are correct Led 1 and 8 is the VCC and GND if connect correctly should light both and if all else is correct it should scroll down the line of leds. 1 after the other if not correct it will skip leds.
Here ya go: EDIT CHANGED A BIT...