I have a ton of sengled A19 smartbulbs and I've been annoyed whenever Sengled's servers go down and my bulbs can't be turned on or off. I've also always been annoyed by having to put stuff on a cloud server anyway and wanted roll my own versions for a while so I'm finally kicking this off.
I hope to eventually reverse engineer the bulbs enough to flash my own firmware so I can have them integrated into a local home automation server. I'm not actually very good with software, just the electronics hardware side so we'll see how this goes...
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06/23/2025 at 06:48
Here's my findings when tearing it down. I started with a bulb that's been acting up that I've been using for a number of years now (they all seem to go screwy, this was just the one doing it now).
I wasn't sure at first if I was going to have to take a dremel to it, but I was hoping to be able to re-use it with minimal work. Luckily I found I can open it up similar to an especially stubborn plastic easter egg. I basically just pulled the translucent plastic globe with one hand and ad base with the bulb socket with the other at a very slight angle from each other and they eventually came apart.
Only some rubbery adhesive holds them together. It wasn't exactly easy and a second bulb that I've had laying around in a closet because I could never get it to pair correctly was much harder to disassemble initially. I hypothesize the heat from near constant use of the bulb I pulled from my light fixture could have made the adhesive easier to pull apart. in either case while pullling, I found a small section of the globe pull apart and was able to work it from there around the perimeter of the seam. Additionally it might be easier to have a second person come in with an exacto knife while the first pulls it apart as I can see the adhesive stretching until it eventially fails, either by stretching or detaching from the plastics. I did find that attempting to use any tool such as a screwdriver or knife to try to pry apart globe from the base started digging/cutting into the soft plastic and I'm trying to keep these as intact as possible. Regardless, I was essentially able to non-destructively dissemblance these bulbs with just my hands.
The Electronics was made of 3 boards. What I'm calling the LED board, an aluminum PCB, a Power board, and an MCU board with an antenna sticking up into the center of the globe from the MCU board. The Power board was soldered internally to the Line and Neutral AC contacts on the base via some small gauge wire. I was actually able to remove both other boards, although very carefully, without breaking the wires at first but I wanted to get a better look at all 3 boards so I went ahead and snipped them. I don't believe there's a non-destructive way of removing the metal base contacts from the base plastic or to de-solder the ~0.5inch wires with the amount of room available. I have no idea how they'd be assembled but It's likely permanently attached so in future dissasemblies I'm not going to remove the power board unless there's a good reason for it. I'll likely have to replace the wires and include a very generous service loop so I can solder things back together without burning things up with my soldering iron
The LED board is very slightly wedged into the base housing but mainly seemed to be held in place due to the friction connection board-to-board header connectors with a little help from some putty like adhesive. I've been using this bulb for at least 5 years so this putty adhesive doesn't seem to be designed to dry. It could also just be a thermal interface material goop that is moonlight as adhesive as it looked to be mainly covering the power supply electronics. To remove it I had to use a small flathead to carefully pop up a corner and I was able to work it from there to disconnect the connector.
LED board
The MCU board. I was able to carefully back the MCU board off of the Power board's connector with some wiggling back and forth with some tweezers and a screwdriver and this pull it out. Since the Power board isn't actually held into place besides with some small wires and goop, I was able to shift it out the way during this disconnection and subsequent removal.
The Power Board. Note, it's definitely corroded and potentially a little toasty. The second bulb I opened that was barely used looks fairly pristine so I assume this is from...