I was going to post my c4s problem amd saw this thread.
Well, my c4s is eating led's. Every six months or so one channel led will go bust and that channel will stop working. I ordered a set from BH and got 4 of them. Now I am down to one. I have changed tubes.
On the rear of the board, where a " jumper" Wire is, there is a discolouration.
Any suggestions. If it matters, I am on 240v.