So my ceiling light suddenly dimmed and didn’t turn bright again. I replaced the led light bulbs in there and now its alls good again.
Why do led lights not simply “burn out” or fail completely? Instead they fail by producing half (or less)the amount of light they used to. This seems like a very odd way to break. Can anyone explain why they break like this?
There are multiple LEDs in the bulb and they’re overdriven, meaning they’re designed to fail. They can be modified to put out dimmer light that will last a very long time but that’s not something most people know how to or will do. Failed ones like you describe are usually repairable also but same issue that most don’t know how to or won’t.
They fail like that because one element dies entirely which messes up the circuit. If the dead one is bypassed with a small resistor the others will light back up.
Look up “homemade Dubai lamps” or as Big Clive likes to call them, “Dooby lamps”. Basically decrease the power by 30% or more by replacing or removing one of current-sense resistors to get a many times longer lifespan. Very easy with lamps that have a linear regulator on the LED board; ones that have a switching regulator inside need to be disassembled further than just popping off the plastic globe (preferrably by milling into the housing from the SMD side of the board because that doesn’t disrupt the thermal design of the LED board). With the latter approach, I can also fix another common issue: the input inductor going open circuit, usually indicated by flashing and a burned-out bypass resistor (most often 4k7 or “472”) − I just short it, I don’t care about the little extra interference if it mskes the bulb work again.