Iffy “smart” bulb; could you help?

[eti]

Hi. I’ve got one of them fandangled “smart” bulbs which I’ve had about a year, and then a few months ago, when on, say 60-100% brightness on the white setting, two or more pairs of the white LEDs (highlighted) go into strobing mode - about 20hz I’d think. Eventually it stops, but it’s very distracting obviously.

I just turned it on at 100% and pressed a couple and they extinguished, but then came back and strobed.

Any idea what could cause this - bad psu components? (Capacitive dropper I assume). In anticipation of “just toss it and replace it” - yeah I am aware of that option. Let’s skip the captain obvious please, I’d like to know the weak points of these devices.

Thank you so much.

[alexnoot]

I've had this problem a lot with cheap LED strips from Ebay etc. Cheap components, driven too hard, bad thermal dissipation and so on.
The LEDs start to fail after a while. The LED dies are usually a series string of tiny LEDs, so there are many points of failiure. The heat could cause some expansion inside it that breaks the string, then it cools down and reconnects -- free strobe light!

[amyk]

Bond wire failure is the likely cause.

That doesn't look like a cap dropper - the low-value resistors suggest this is a current regulator, probably linear.

[jmelson]

Inspect the solder joints on the LEDs and resistors in the area of the strobing ones.  There might be a bad joint that is actually accessible.

Jon

[nali]

FWIW I've investigated intermittent LED failures in matrix panels in a high brightness / high ambient environment and like amyk says it was down to bond wires in the LED itself. I even de-soldered some and hooked them up using magnet wire - and could make them work/fail just by squeezing the resin body with a pair of pliers.