VU Meter broken on RX2

The Volume LEDs on my RX2 have stopped working.

They don't light up on power on and do nothing during play or in service mode. 

Since they worked the last time I used the unit before I moved into another home, I have the assumption, that maybe to cable did get disconnected on the inside. How likely is that? Is it soldered?

I've opened the back of the unit but there was no immediate acess to the board.