It VERY much sounds like controller is dead. Ive had the same thing happen. In my case it was not the bridge or pi because I took a known good bridge and pi from another controller  and plugged that into my faulty controller and got the same result and that was a :

1. Power with blank white led screen
2. 1 green led controller

=

Dead controller.

The cheapest fix is to use a controller from a neptune. I beleive this is confrimed that the neptune controllers DO work with our pi and bridges. I dont know if more needs to be done or not. I believe neptune controllers can be found cheaper than Titan controllers on EBay.

I have your exact same problem. If I get time, I will diag mine. It could be one of the surface mount capacitors. I have a capacitor wizard that can test "in circuit" capcacitors and resistors. If I can get it working, Ill post how.

Vegas