Richard,
If the cell has no lights at all, then either the cell is bad or the power center is bad.
With the cell in a bucket of plain water, you can turn on the power center and then measure the voltage going to the cell..
The cell cable has 4 wires... The Red and Black wires carry the DC voltage to run the cell, including the lights. It should be 35 to 40 volts DC... (Note this is how my EasyTouch works, but I assume it is basically the same for the Power Center. The Power Center has a transformer which supplies AC voltage to a power supply board, which converts the AC voltage into the DC voltage used by the cell.
Thanks,
Jim R.