Failed 2D LED replacement lamp. (with schematic)

  • Published on Aug 22, 2019
  • I was sent this lamp by Richard, who had inadvertently put it into a higher power rated fixture.
    It overheated and failed due to the higher current passed by the fixtures existing ballast.
    It's odd that the lamp even fitted onto the higher rated lamp connector. I was always under the impression that they were keyed according to the rating of the fixture.
    The circuitry is very simple, since it relies on the existing ballast or electronic power supply to limit the current through the LEDs.
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  • Science & TechnologyScience & Technology

Comments • 220

  • NoSaltiesAnd RoosHere
    NoSaltiesAnd RoosHere 3 months ago


  • hans.preis hans.preis
    hans.preis hans.preis 4 months ago

    Wats the difference between a Bitchrectefier and a Bridgerectumfrier?

  • penguins forall
    penguins forall 4 months ago +1

    I absolutely hate the "stand in" replacement led lights. They waste time and money making things "compatible" in absolutely no sense of the word except some false comfort. On the one hand the idea of reusing the fixture makes some sense except you have to replace a bunch of pieces and rewire it. The fixture doesn't need reflectors since they are in the LED chips so it sticks off the ceiling when it doesn't need to. Many of the lights are super dangerous with live AC sticking out on an end. As the user intuitively thought you could make the light dimmer using a lower watt rating. You know what else LEDs can do? Dim with a dimmer which can be built into the fixture.

    You can buy an entire light fixture that's pretty gorgeous for $35 dollars with LEDs space out nicely giving a super consistent look and flat on the ceiling instead of sticking out more than an inch since the reflectors are in the chips all it needs are a diffuser. Using aluminum backed strips that screw on the board would make the most sense if you wanted the ability to replace them. Except I haven't seen anyone do that yet. Plus if they are using isolated DC (which they should be) you wouldn't even need to turn the thing off to switch the LEDs out. Not that you'd need to very often.

    I noticed recently a very nice LED light fixture with good SMPS components seemed pretty durable except in the usual Chinese way a few "unneeded" components were left out including the surge suppression and the fixture got fried from a moderate surge. So its things like which turn people off from the idea of having the light embedded in the fixture.

  • CubbyTech
    CubbyTech 5 months ago

    I still don't understand how you can 'push' more current to a bulb - doesn't it just use what it uses? Silly to design in such a way and go to all the trouble to indicate NOT to use it in a 28 or 38 watt fitting.

  • Matheus Moreira
    Matheus Moreira 5 months ago

    That lamp's shape reminds me of Pretzels. Not the kind I would like to eat, though!

  • bob s
    bob s 5 months ago

    In the fluorescent tube fitting it's a led lamp with an inductive dropper power supply. If it's used together with two Poundland capacitative dropper 6 watt led lamps the overall power factor should be pretty good.

  • Brenden Michelus
    Brenden Michelus 5 months ago +1

    Why would anyone think that putting a lamp in a fixture with a _higher_ wattage rating than the lamp would make it dimmer or use less electricity?
    If you put a lamp in a fixture with a _lower_ rating than the lamp, _than_ it would be dimmer. On the other hand, the exact opposite would happen
    if you put a lamp with _too low_ of a wattage rating for the fixture. Driving the lamp at a higher voltage caused the current to increase too high,
    causing the wattage to surpass the lamps rating, causing higher energy dissipation, overheating the LEDs and cooking the lamp to death.

  • cremationpete
    cremationpete 5 months ago

    According to toolstation catalogue, the fern Howard 2D are only for use in HF ballasts (which under-run fluorescent lamps compared to mains frequency) hence the two resistors on each side of the lamp replicating the cathodes of a fluorescent lamp to trick the HF ballast, normally if a cathode goes open circuit the HF ballast cuts out. It would appear that these lamps aren’t designed for use with a simple inductive ballast that would do little to limit the current.

  • Terry C.
    Terry C. 5 months ago

    So if everything checks out, will it still work or no?

  • Barry Greengrass
    Barry Greengrass 5 months ago

    Clive what the name of the spudger you like to use please

  • Michael O
    Michael O 5 months ago

    Seems like it would have been trivial to add fail safe circuitry here. When dealing with an ambiguous socket type, manufacturers really should offer this.

  • Abdelkader Elbachir
    Abdelkader Elbachir 5 months ago

    Byby for good

  • nfc153
    nfc153 5 months ago

    "inox" = stainless, generally not the hardest of steels.
    While Victorinox have found a reasonable mix for their alloy, it seems the spudger manufacturer hasn't bothered. At least it was cheap. I hope it was cheap.

  • Jim Lush-Smith
    Jim Lush-Smith 5 months ago

    @bigclive how can I send you an amazing chinesium led light / speaker which was sent to me in error. I would love to see a tear down video of it. How can I send it to you?

  • Colin Wilson
    Colin Wilson 5 months ago

    Dunno why, you may have already seen this, but for some bizarre reason I immediately thought of you

  • Kettle Vale
    Kettle Vale 5 months ago

    I bought one from Screwfix, broke in 48hrs. Replacement has lasted months however.

  • Jose Silveira
    Jose Silveira 5 months ago

    I'm guessing that, if you connect all four led PCBs in series, it will light up safely, independent of having a ballast or not.

  • Koto-Sama
    Koto-Sama 5 months ago

    Why did you started pausing so much?

  • Casimir Konrad
    Casimir Konrad 5 months ago +1

    This kind of socket is rarely used in Germany.
    Normally 4pin-lamps have no starter inside (just two pins for each electrode/cathode) and need an external ballast and a starter (or an electronic ballast), while 2pin-lamps do have a starter inside and need an external, inductive ballast.

  • Michael Mitchell
    Michael Mitchell 5 months ago

    It’s what is called cheap china shit. A lot of these cheap Chinese leds about. They use cheap or even fake components. I do electronics and today you see so much cheap electronics items that fail and all from China. A lot of this stuff comes of eBay or amazon. Even some of these led lights can be very dangerous. So please watch yourself when buying cheap led lighting. You just got to watch yourself these days in buying cheap chargers,led lighting, etc. I seen many fake components too like capacitors,diode,resistors and evening ic chips and others parts.

  • Graham Langley
    Graham Langley 5 months ago

    Looked at these replacements when I wanted to change the 16W 2D fitting in the porch here to LED.and wasn't impressed by any of them. Changing the fitting wasn't an option so I ripped the fitting's internals out, made up an ali heatsink/mounting plate, fitted the LEDs from a couple of 5W GU10 bulbs on it and connected them to a constant-current LED driver from CPC.

  • mavos1211
    mavos1211 5 months ago

    Sorry I haven’t really seen many of your videos recently Clive so i have not been around to like and comment.
    I just haven’t been in a good place lately
    But I’m sure I’ll snap out of it eventually.

  • Jay Brooks
    Jay Brooks 5 months ago

    Wrong kind of metal? More like Not tempered

  • Robert C
    Robert C 5 months ago

    I've seen people install 16W 2D tubes in 28W fixtures before, and they don't last long, for obvious reasons. I saw one in a pub toilet was really nice and bright, but had a nasty burn at one end that looked like hot coals (i.e very blackened with a bit of a dim red glow showing through).

  • MD4564
    MD4564 5 months ago

    Wouldn't be cheaper for a fuse than resisters ?

    • bigclivedotcom
      bigclivedotcom  5 months ago

      Double feature. Current limiting and fusability.

  • cmyanmar13
    cmyanmar13 5 months ago

    Can you do a teardown of an infrared thermometer?

  • Andrew Meredith
    Andrew Meredith 5 months ago

    If you mind me asking Clive, what type of meter were you using in this video?

  • Alan King
    Alan King 5 months ago

    You can’t win with these 2D fittings. If you fit the non ballast type of LED fitting you can Guarantee if it fails someone will try and replace it with a fluorescent. If you fit the ballast compliment type and it fails someone will try and replace it with the non ballast type led.

  • Jonathan Brown
    Jonathan Brown 5 months ago

    3:53 apparently Clive's "OK" sounds like "OK emy" as it sets off Huawei's crap voice assistant

  • Lee Porte
    Lee Porte 5 months ago

    Humn.... From memory the centre of both the 16w and 28w lamps was the same, however the 16w was about 2/3rds the size, so you couldn't fit a 28w lamp in a 16w fitting.

    • Lee Porte
      Lee Porte 5 months ago

      @Graham Langley I just can't quite remember (which will bug me all day), G series lamps I can still remember. I was in the lighting industry years ago.

    • Graham Langley
      Graham Langley 5 months ago

      IIRC there's some form of keying on the base but I've no longer got any 2D fittings here to check on.

  • Benedict White
    Benedict White 5 months ago

    I wonder what would happen if you ran it with the correct ballast.

  • jacqueline mnich
    jacqueline mnich 5 months ago

    Get some tin snips and trim your bloody feeler gauge , you have till the tool comes to a end and that's a few trims

  • Asa Mitchell
    Asa Mitchell 5 months ago +1

    16w and 28w 2d lamps have the same sockets they are eaither 2 pin or 4 pin but the socket is the same size

  • 28YorkshireRose12
    28YorkshireRose12 5 months ago

    This has got my interest aroused now! - I have two used SOX replacement LED lamps. Essentially, they are a direct substitution for the normal yellow SOX lamp. I asked the guy "Do you leave the control gear in situ, or do you rewire the luminaire (lantern) so as bypass the ballast and igniter?" . He said to bypass them, however, given that these are second hand, I first tried them in a normal b22 lamp socket. One lit up for a couple of minutes, then dimmed to virtually nothing. The other didn't light at all, until you gently press on several of the LEDs (definitely faulty), but I am wondering now if the first one should have been connected via the ballast, like the lamp you have dismantled here?

    On another note, or could that be "dulcet tone"? I have noticed of late that my four kittens (born in February, this year) have taken a definite liking to our Clive. They sit close to my Hi-Fi speakers with a look of contentment and ecstasy about them. As soon as the video ends, they're off to play again. . . I think Clive might secretly be a cat whisperer! 😾🐈 🐯 😹

    • jak mak
      jak mak 5 months ago

      Maybe the kittens like his whiskers too 😻

  • kilrahvp
    kilrahvp 5 months ago +1

    Or the lamp didn't actually fail but the owner stopped using it when they noticed it was half burning...

  • Martin Rygaard Lassen
    Martin Rygaard Lassen 5 months ago +1
    What do you make of this:

  • pmailkeey
    pmailkeey 5 months ago

    Why do they make these things so complicated ? Why not run 80 LEDs in series across 240V dc with a capacitor and be done with ?

  • Anders Van de Gevel
    Anders Van de Gevel 5 months ago

    @bigclivedotcom working as a projects sparky for (herp-derp) Council, I get to see the occasional interesting LED replacement lamp.
    I have a couple of Kosnic 2D 4-pin ones, which I thought cheap and nasty until I saw the plastic nastiness you dissected here xD
    One thing interesting to note with these is, as they are designed to run on 230v directly, the maintenance sparkies (using the term 'sparky' VERY loosely) tend to bung them right in and fook off.
    Now these Kosnic ones (reclaimed during refit >.>) run fine like that, but, stick the power meter (not a flickery HOPI, but one can't have everything) and you find it's sucking around 3x the rated 87mA... ooer missus, what's going on here?
    Quite simply, the maintenance 'sparky' hasn't removed the cap from the control gear...
    I keep meaning to send you some odd bits to dissect, I'll include one of these (when I remember xD).

  • Siana Gearz
    Siana Gearz 5 months ago +1

    Would buy Clive's branded high-quality spudger.

  • Karen O
    Karen O 5 months ago

    Probe that Plastic Housing - ha ha Looks like it added some contribution to 'output'. =p

  • Tyrone Nelson
    Tyrone Nelson 5 months ago +1

    You would have thought that current limiting would have been built into the led fitting itself regardless of what fitting it went into, i don't get it.

  • ttony478
    ttony478 5 months ago +1

    Pity they didn't use a more sophisticated power supply to avoid this issue.

  • pmailkeey
    pmailkeey 5 months ago

    1:48 "Not the lamp's fault" - Oh yes it is ! If they can't be bothered to put a resistor or something to drop the current, it's the lamp design fault. I guess I have similar issue with fluo tubes - new tubes the ends go black and the tubes fail in a few days. Put old tubes in and they're absolutely fine.

    • stdorn
      stdorn 5 months ago

      @pmailkeey if that were the case the manufacturer wouldn't say don't use with higher wattage ballasts it wouldn't matter according to you. Those 1.8 ohm resistors aren't going to drop hardly anything if you take 220v fully Rectify it and filter it you can multiply the 220 by 1.414 to come up with the DC RMS voltage which would be 311v divided by 24 LEDs in series you would be running these LEDs at about 13 volts a piece they would burn out so quick you wouldn't even see them light.
      If I'm missing something here please explain what would drop the excess voltage if no ballast were used?

    • pmailkeey
      pmailkeey 5 months ago

      @stdorn No - if the power consumption is under or equal to the lower power ballast, the ballast is effectively ignored and the lamp would work wither either ballast or even none at all.

    • stdorn
      stdorn 5 months ago

      The original ballast is the current limiter it is designed to put out 28w, if you run 28w into a 11w bulb it will fail. Not the bulb fault. Adding more resistance would mean it would be underpowered when run from the correct ballast.

  • pshq
    pshq 5 months ago

    Do anyone recognize the logo thing printed on the brown PCB? Is it a logo of the manufacturer of the PCB? I've seen it on a pirate video game cartridge PCB and initally thought it's the secret sign of the pirates, but now I'm not that sure about it...

  • Sulev-Madis Silber
    Sulev-Madis Silber 5 months ago +2

    i didn't know they make such ones without current limiting!

  • Andy Pandy
    Andy Pandy 5 months ago

    They put the standard type like that in every council house/housing association bathroom in this area, but the only 1 you can put 2 different tubes in, so the local hardware store started stocking them, £15+ each for either type.

  • Quentin Smith
    Quentin Smith 5 months ago

    @bigclivedotcom The letter said he removed the starter entirely. So there was no current limit at all. I'm surprised it worked at all and didn't just instantly pop.

    • stdorn
      stdorn 5 months ago +1

      the starter does nothing to limit current, as Clive explained it just send the ballast power to the filaments to heat them and then opens again.

  • FrontSideBus
    FrontSideBus 5 months ago +6

    A decent quality (GE or Philips ) normal 2D lamp will outlast any of these horrid LED replacements tbh...

  • Gustav Fenk
    Gustav Fenk 5 months ago +1

    Would it be possible to design these LED lamps with the current limiting built in to prevent overheating like this?

    • pmailkeey
      pmailkeey 5 months ago

      Next silly question.

  • Fixerbob
    Fixerbob 5 months ago

    Fabulosly melty moments with Big Clive

  • RFC3514
    RFC3514 5 months ago +1

    1:59 - Stress on the first syllable (i.e., SEHsamo, not suhSAmo). As in Ali Baba's "open Sesame".

  • Boonedock Journeyman
    Boonedock Journeyman 5 months ago +7

    Maybe a video about ballasts and starters would be good. Much confusion there for LED people.

    • Brian Deschene
      Brian Deschene 4 months ago

      Boonedock Journeyman
      Here you go...

    • Oliver Dawson
      Oliver Dawson 4 months ago

      Already done one a while ago

    • Shaun Clarke
      Shaun Clarke 5 months ago +1

      I think he's done one in the past already?

  • JendaLinda
    JendaLinda 5 months ago

    What happens if you connect this kind of lamp to the electronic ballast?

  • Andreas Dill
    Andreas Dill 5 months ago

    Your schematic is wrong. This type of lamps work with elecronic ballasts. The LED lamp relies on the current regulation of the electronic ballest. the voltage over the LEDs would be lower, so with the given current the wattage would be lower.
    The resistors emulate the heated cathodes to trick the electrnic ballast.

  • Antonio Claudio Michael

    Great video clive

  • webchimp
    webchimp 5 months ago

    Those uncropped wires may be going into a plastic housing but they are right next to a nice aluminium backed PCB

  • Mick Ellis
    Mick Ellis 5 months ago +1

    What spudger do you normally use Clive?

    • Mick Ellis
      Mick Ellis 4 months ago

      Hay Clive,
      Yea I sort of figured that out. Dumb question. Thanks

    • bigclivedotcom
      bigclivedotcom  5 months ago


  • Simon Howroyd
    Simon Howroyd 5 months ago +4

    Thought you were going to plug it in via a capacitive dropper or something, sad face

    • Simon Howroyd
      Simon Howroyd 5 months ago

      @bigclivedotcom ah yes forgot you were over in Europe ;-) Hope you're having fun!

    • bigclivedotcom
      bigclivedotcom  5 months ago +1

      I'm not at my workshop right now. Otherwise I would have roughed something up.

  • willrobbinson
    willrobbinson 5 months ago +1

    I thought 2D was well past in history as it should be now more led type replacements

    • Tom
      Tom 5 months ago

      I believe it's intended for retrofit to the existing lamp. Unless I misunderstood.

  • rimmersbryggeri
    rimmersbryggeri 5 months ago +1

    Maybe you could explain some time how the ballast for a car xenon lamp works.