Q:

What does that mean if my LED light bulb starts blinking when I turned it on?

I have an LED light bulb: Philips 60W incandescent equivalent
I've owned it for about a year and have been very happy with it.  This morning when I turned it on, it started blinking.  Not flickering, but a very deliberate one second on, one second off, one second on, one second off.  This continued until I fiddled with the bulb at which point it came on and stayed on. 
It has never done this before.  I unscrewed the bulb and it rattles.  Something in it may be broken, but it still seems to work.    I couldn't find anything on the Philips website about this type of behavior.  Does anybody know what it means?

A:

I called Philips about this issue.   They said that it indicates that the bulb is broken and needs to be replaced.  Some LED bulbs have enough electronics in them that they are able to have diagnostic circuits and to report errors in this manner.

A:

I experienced similar effect, but affecting a number of led lights on the same circuit where incandescent lights worked fine. Turns out it was a poor connection on the common neutral return.

A:

I've repaired 3 of my LED lights that were blinking by replacing both electrolytic capacitors. Capacitance was OK, but the capacitor resistance (ESR)  was too high on both of them

