Andy Burns has brought this to us :
Harry Bloomfield wrote:

'corn-cob' LED, which has light output around the
entire lamp, except the base.

That's the only type where I've had the actual LEDs die rather than the power
supply, you could hear them 'pinging' as they cooled down after use, so guess
they were driven stupidly hard with poor cooling.

I only have one such lamp, that in one of those Georgian style outside
lights, providing some light in my drive. That was installed 12 months
ago, in a new fitting and is powered by an ancient Sangamo mechanical
solar clock. It comes on at dusk, goes off at around midnight. None of
the LED's in the lamp have failed so far.