Spontaneous LED bulb teardown — IKEA 200lm candle

It has happened again!

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After about 2 years of very mild usage (bathroom mirror light), an average on-time of about 5-10 minutes per day, yet another of my many IKEA LED lamps has died. This time it was a 4.3W one, not exactly high power.

Below you’ll find a couple of images, the results of a few tests I made, and probably some inevitable ranting.

After popping off the glass dome [insert screw driver & wiggle a bit] and removing 2 screws, I opened it up and expected a blown capacitor. None of that. I tested all diodes [OK] and most capacitors, especially the electrolytic ones. At least as far as capacitance goes, they were OK. Something else must have given out.

I tested the bridge rectifier, it was still very much alive. All of the ceramic capacitors I tested looked good too. No obvious tell-tale signs of a failure (cracked packages, strange liquids, obvious carbon deposits after releasing the magic smoke).

Then I directed my attention to parts that looked fine, but still might have been dead.

I measured the resistance of this inductor and came up with several MOHm, which didn’t feel right. Unfortunately I damaged it further during removing it from the board. No sure way to tell if it really was dead before.

Finally I decided to take the little transformer apart. The primary winding had a resistance of 47mOhm, quite nice. It also used double-insulated wire, 2 layers of insulation. All the other windings were just ordinary enamel-coated wire. There were at most 2-3 layers of the yellow sticky tape between the windings.

And guess what, the LEDs still work! Just like some time ago when one of the 400lm IKEA ledare bulbs died. Same story:IKEA ledare 400lm

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All that remains now is a heap of junk and yet another LED + heat-sink, which I might convert to a DC lamp later.

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How long was this lamp in service? About two years. How long was it on? Not a lot. This lamp was used to illuminate my bathroom mirror, so it might have been used 5 to 10 minutes per day. Taking 10 minutes, the cumulative on-time of this lamp was about 5 days, not a lot.

I think something is clearly wrong with the power-supplies of these LED bulbs. This one did not have any thermal compound in it, which should have helped with cooling a bit. The 400lm bulb didn’t have any either. I think I see a common thing here.

The 400lm bulb has a nice metal body for a heat-sink, but didn’t use any thermal compound around the power-supply to make use of it. Only the LED-board was allowed to dump excess heat into it. The LEDs survived, the power supply died after about 24 months as well.

Does IKEA do this on purpose?

I find it sad to make the power-supplies a weak point in the design of these LED bulbs. They could live much longer, the LEDs do quite well.


This video may be of interest

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6 Responses to Spontaneous LED bulb teardown — IKEA 200lm candle

  1. John Zammit says:

    I think it is condensation entering the bulb more than anything else.

  2. Wolfram says:

    You could seal the next IKEA Bulb around the socket using PLASTIK70 or a similar isulation spray and then test. If it lives longer, it could be condensation.

    BUT:
    I had a discussion with a chinese LED manufacturer some time ago and he told me that the buyer always look only on the quality of the used LED components, all the power supply nobody takes care of. It just has to be “cheap and cheaper”

    • robert says:

      Well, if the power supply’s main attribute is to be cheap, then why did they use a Texas Instruments controller IC in the 400lm bulb? They certainly are not the cheapest option.

      Unfortunately I can’t reconstruct for sure what has failed in this bulb, but it wasn’t the diodes or capacitors, maybe it was the inductor.

      I find it a bit unusual that the power supply isn’t potted with thermal compound. That should help reduce hot spots.

      Another case of “Planned Obsolescence” maybe?

      It’s also quite annoying that IKEA don’t seem to do any refunds within the 24 month “warranty” period. When I tried, the resistance was massive. It is probably legal in Germany (6 monats beweisumkehr…), but it doesn’t increase confidence if LED bulbs that are supposed to last 25000 hours break down way before that and you can’t get a refund.

  3. Jerry Cupples says:

    Robert, these teardowns are very interesting. Generally, putting power supplies and LED arrays into A19 bulbs is an engineering challenge. Obviously, it’s fitting a new technology into a century old package, so there are issues.

    I have only recently started replacing the CFL lamps in my home with LED types. Here in the US, Walmart is selling an 800 lumen at about $5, I have a few. IKEA had a “sale” two weeks ago (in Frisco, TX) – all their LED lamps 1/2 price! Bought a bunch of the 600 lumen for $2.24 each (LED1339G10). They look a bit different than your teardown, rated 9.5W.

    Seemingly, the power supply is the first failure for the IKEA. I had a 60W equivalent Walmart “Great Value” in my garage, running base up. It was operated for about 1 year, (a few hundred hours) and it lost a lot of brightness, but worked. I replaced with an IKEA, we will see how it does.

    Finally, thank you for your work in this, it is very interesting and valuable.

    • robert says:

      I hope your IKEA LED bulbs last a bit longer than mine!

      My suspicion is that the power supplies might get a decent life-time if they were potted in thermal compound. So far none of the IKEA LED bulbs were gifted this little helper.

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