[smokinreefer]

To identify which LED pad is the problem:
The pads are in series, so when one is done, they will all stop working.
Try bypassing a pad by shorting it.
Use a copper wire and connect B+ to B-.
When you bypass the faulty pad, the others will light.

When you remove the cover, you will see the connections are labeled.
So just follow the steps above.

I used this method to isolate and replace a faulty pad.
I'm a cable guy, so I just used a small piece of copper core from a piece of coax