DA had written this in response to
http://www.thestuccocompany.com/main...ch-403425-.htm
:

Percival P. Cassidy wrote:




We got a letter from Costco today inviting us to return the
"Lights of
America" LED bulbs we had purchased because they do not live up to
the
claimed life of 20K hours. Four different SKUs are listed.

Sam's Club has sold some of these as well, but no communication so far
from them.

Perce

They are *SO* bad that I have to repair one or two literally every week.
As I'm writing this, two out of four are dark, I just did not have time to
work on them yet. Irony: they are lighting my electronics workbench and so
I just bring them down without even getting up from the chair and reach
for a replacement white LED and 3 minutes later it's going back up and
works until another one of the original LEDs gives out.

Thankfully (in terms of repair, not use of course), they are *SO* bad that
even glue that holds the socket prongs body to the transparent cover
crumbles (!) right after you drive a knife into the crack between the two
parts and give it a slightest twist.

I have a little rig devised specifically to test the LEDs in the LOA
fixture but sometimes you can just see a dark spot inside the LED that
indicates a burnout.

There are 24 LEDs in each light and I estimate that after 18 months of
use/repair cycle there will finally be no original LEDs left. I don't know
if it will increase time between failures too much though because the
whole idea of powering a string of serially connected LEDs from 120V seems
faulty to me - each (good) LED does have a 40,000 hours lifespan or so but
having 24 of them in series, you'll have to stack the MTBF up (calculating
MTBF properly is not my cup of tea) and for the whole fixture it will be a
small fraction of what the single LED would last. My next LED light will
definitely be a 12V parallel - connected LED type.

Anyways, sorry for the long rant, these lights have been an eyesore for
the past year for me, I can't wait to use the earliest opportunity to get
rid of them.

If you are not able to easily repair them yourself, there is no question
about it - return them ASAP. byt the way, Wallmart still sells them ...


---------------
\//.

DA wrote:

We got a letter from Costco today inviting us to return the
"Lights of
America" LED bulbs we had purchased because they do not live up to
the
claimed life of 20K hours. Four different SKUs are listed.

Sam's Club has sold some of these as well, but no communication so far
from them.

They are *SO* bad that I have to repair one or two literally every week.
As I'm writing this, two out of four are dark, I just did not have time to
work on them yet. Irony: they are lighting my electronics workbench and so
I just bring them down without even getting up from the chair and reach
for a replacement white LED and 3 minutes later it's going back up and
works until another one of the original LEDs gives out.

Thankfully (in terms of repair, not use of course), they are *SO* bad that
even glue that holds the socket prongs body to the transparent cover
crumbles (!) right after you drive a knife into the crack between the two
parts and give it a slightest twist.

I have a little rig devised specifically to test the LEDs in the LOA
fixture but sometimes you can just see a dark spot inside the LED that
indicates a burnout.

There are 24 LEDs in each light and I estimate that after 18 months of
use/repair cycle there will finally be no original LEDs left. I don't know
if it will increase time between failures too much though because the
whole idea of powering a string of serially connected LEDs from 120V seems
faulty to me - each (good) LED does have a 40,000 hours lifespan or so but
having 24 of them in series, you'll have to stack the MTBF up (calculating
MTBF properly is not my cup of tea) and for the whole fixture it will be a
small fraction of what the single LED would last. My next LED light will
definitely be a 12V parallel - connected LED type.

Anyways, sorry for the long rant, these lights have been an eyesore for
the past year for me, I can't wait to use the earliest opportunity to get
rid of them.

If you are not able to easily repair them yourself, there is no question
about it - return them ASAP. byt the way, Wallmart still sells them ...


We haven't had any as long as a year yet, but so far the only one giving
trouble is one of three R30 bulbs that normally are on for several hours
every day. These are bulbs with a regular ES base; we use them in our
track-light setup.

Perce

In s.com, DA wrote
in part:

There are 24 LEDs in each light and I estimate that after 18 months of
use/repair cycle there will finally be no original LEDs left. I don't know
if it will increase time between failures too much though because the
whole idea of powering a string of serially connected LEDs from 120V seems
faulty to me - each (good) LED does have a 40,000 hours lifespan or so but
having 24 of them in series, you'll have to stack the MTBF up (calculating
MTBF properly is not my cup of tea) and for the whole fixture it will be a
small fraction of what the single LED would last. My next LED light will
definitely be a 12V parallel - connected LED type.

Most LED failures do not affect their conductivity. The usual reason
for an LED to be considered "failed" is for it to have faded excessively
from number of operating hours (or combination of number of operating
hours and temperature).

I am aware of LEDs failing open, but that is usually either from severe
abuse or from the LEDs being cheap rubbish, with thermal cycling
(generally with repeated very large change in temperature) being in a
distant third place.

- Don Klipstein )