Taking apart a failed 10W LED bulb

Apr 02, 2019

The bulb

I’ve had a GE LED11DAV3/827W bulb in the hallway for quite a while, but it has the habit of flickering on & off almost immediately after flipping the switch.

I was curious about what was causing this, so I decided to take it apart.

PSU PCB

Here are some shots of the power PCB after carefully removing the glass cover & the heat transfer potting:

Bottom of main PCB
Bottom of main PCB
Top of main PCB, with BJT model number
Top of main PCB, with BJT model number
Top of main PCB, with coupled inductor model number
Top of main PCB, with coupled inductor model number
Side view of main PCB, with bulk capacitor model number
Side view of main PCB, with bulk capacitor model number
Top of rectification PCB
Top of rectification PCB
Bottom of rectification PCB
Bottom of rectification PCB
Side view of rectification PCB, with output filter model number
Side view of rectification PCB, with output filter model number

Cause of failure

Heat discoloration of bulk capacitor heatshrink
Heat discoloration of bulk capacitor heatshrink

It’s hard to say what the real cause of failure was here. The bulk capacitor obviously doesn’t look too great, but measuring it gives the correct value. The BJTs also seem to measure correctly.

I’m unable to connect the board to power and test it that way since I broke it during disassembly.

Unfortunately it looks like there’s no way to figure out what failed.

Schematic

Power supply schematic
Power supply schematic