…they did work as expected.
I recently ordered 3 of these 4W LED light bulbs. They claim to have 470lm, or about 117lm/W, which is quite a good efficiency for cheap consumer-type LED bulbs.
Unfortunately only 1 out of 3 works.
The first offender has 2 dead filaments
The second offender is even worse, it has 2 filaments that do a little disco light show. Lots of random flickering. Bloody annoying!
Requested an RMA.
I thought it would be interesting to show the micro-structure of the COB assembly with the LEDs. I may attempt a tear-down later.