Major malfunctions in elktown!

I just returned from a 5-day trip and the "pipe-light" is out... I checked the drivers, but they're ok. The LEDs glow a tiny amount when powered.

I also checked the thermal switch/pump circuit and they work fine as well...

Next thing I guess is to test the LED-string and exclude one led after another until I find the ones that are burnt out or whatever.

My girlfriend has been watching the place and she casually mentioned something about the fire-alarm (on top of the cab) going off this morning... WHAT!?

I hope the circuit stops when one LED fries and the rest are good.

Need some help on this one!

Plants are fine, btw. Pulled a male, so down to 4.