The EOL mechanism of LEDs, is to gardually dim over life.
So i think that like my UV 12 LEDs flashlight, that have one LED not working because of a fault in the assembly contact, in this LEDs panel, the dark LED probably have a same problem.
I would say more likely killed by voltage spikes. The ones here suffer from a lot of early panel failure, where one half of the unit does not light up at all.
So i think that like my UV 12 LEDs flashlight, that have one LED not working because of a fault in the assembly contact, in this LEDs panel, the dark LED probably have a same problem.