On 02/10/2015 12:39, Andy Burns wrote:
wrote:

I now have to report that one of the lamps has failed entirely. So
that's just 16 months of life, maybe 2 hours a day = 1000 hours.

My second one managed more than that, lets say 18 months at 6 hours/day,
3000+ hours, nothing like the 25,000 headline figure on the packaging.

I contacted ALDI by email, their response was 12 month warranty, tough.

I didn't want to faff about convincing them to refund/replace, so I took
it apart, hoping I might find an obviously failed capacitor in an easily
accessible location, no such luck.

Fairly normal layout, all potted in soft silicone, input resistors to
mains rectifier to bead-type smoothing caps, then there was a wirewound
resistor feeding into the ICs/transistor chopper section, feeding small
transformer and output smoothing caps.

The wirewound resistor was burnt to a crisp (the lamp didn't fail
spectacularly just flickered then faded away) all the surrounding SMDs
looked like their solder was cooked and discoloured, one surface
resistor had melted away from the PCB, so looks like long term overheating.

That sounds more like the switcher failed dead short to ground and the
current limiting resistor and all ancillary components were cooked.

Seems like the guts of the 13W are pushed too hard.

Boo.

Indeed, sod lidaldi for LEDs in future, the LEDhut ones of similar age
(fewer hours and lower wattage) are still going OK, but I'll try some
with a multi-year warranty, what were those recommended by Adam,
"Integral" ?

I have only had one of mine from any source fail so far. The 25k hours
is for the bare LEDs - I reckon 5k hours is pushing it where the
capacitors are concerned and much less if it is cooking in an unsuitable
hot enclosure. LEDs don't make much heat but what heat they do produce
is more than enough to dry out capacitors over time.

--
Regards,
Martin Brown