2 rows of 9 LED’s corresponding to each of the possible connector
pins and one for the screen (or ground) connection. As each pin is
activated, the LED’s indicate all connections associated with that
pin, so that short, open and crossed circuits can be easily found.
e LED’s also show the possibility of high resistance or leakage
connections. 2 LED’s indicate a good digital network connection,
either Straight through, or Crossed over.