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Maintenance: Replacing Bulb in 550EX Flashgun

September 20, 2010

A couple of months ago my flashgun fell off a lighting stand (then bounced rather impressively off a tiled floor)! Priced over £200 and now fallen from shoulder height you can imagine how my heart sank. Surprisingly, after some investigation, it looked like it was only the lamp that had broken. Amazing really, although I wouldn’t advise it to other photographers!

Kent Wedding & Portrait Photographer

Canon 550EX Speedlite

For 7 years I worked at ITV as an Electronics Maintenance Engineer. Fixed pretty much every kind of kit in the broadcast environment, at surface mount component level. So I didn’t think a cracked lamp was going to be too much of a challenge!

Naturally, being a photographer, I thought I would take photos of the whole process. I hope someone, somewhere, someday finds this useful to them 🙂

After a few false starts with companies trying to sell me the whole ‘repair and parts’ service, I was able to purchase the lamp (part number: y17-3159-000) from a company recommended to me via the Canon support website. I was hoping it would be a complete assembly but that wasn’t possible. I think that is only possible with the 580EX speedlite lamps. The lamp (including VAT and postage) came to approx £18. Two of the ‘repair’ companies wanted over £100!

Let’s get started..

Firstly I advise that the flash be powered and zoomed to the maximum focal length, as this brings the lamp assembly to the front of the unit. I didn’t do this til the flash was disassembled and ended up getting a nasty ‘bite’ off one of the capacitors when I accidentally caught it with my little pinky! DOH! I believe these capacitors have a discharge resistor across them so they should discharge on their own, but may take a while. Be careful.

Remove the two visible screws on the underside of the flash head. With a small flat head screwdriver, lever off the two rubber pads on either side of the flash. These are only stuck on but are quite stubborn the first time you try to remove them – try not to damage the plastic casing when you do this. There are 4 screws under each rubber pad. Remove these.

Kent Wedding & Portrait Photographer

Remove rubber pads and all visible screws

You need to remove the first half (underside) of the head casing; It’s a little fiddly. It’s clipped to the top side at the front of the head and I found just careful, but forceful, wiggling (technical term) encouraged it to come loose. A bit of screw driver prodding may also have occurred!

Kent Wedding & Portrait Photographer

The front lens will probably drop out by itself and then you can get your first look at the lamp. It was clear why mine was no longer working!

Kent Wedding & Portrait Photographer

Remove the rest of the head casing by undoing the screw either side of the white moulding.

Kent Wedding & Portrait Photographer

Remove remaining casing from flash head

Kent Wedding & Portrait Photographer

Two small screws either side of white plastic moulding, removes the top head casing.

The insides of the flash head will now be free of casing. I found it useful to lift off any sticky tape and unravel the wires from around the white moulding. This allowed the flash head to be worked on with some distance to the rest of the flash unit, without having to actually disconnect any wires.

Kent Wedding & Portrait Photographer

Well engineered sticky tape secures lots of wires to the flash head

I also removed the circuit board from the flash head, but I don’t remember getting much benefit from this. This was also the moment at which I stupidly discharged the flash with my hand!

Kent Wedding & Portrait Photographer

A couple of screws hold the circuit board in place

There is one screw that holds the lamp module inside the white moulding. Be careful removing this; the black plastic piece will also come off and a small spring shot past my ear at this point too!

Kent Wedding and Portrait Photographer

If the flash is zoomed in, this black piece will be near the top of the white moulding. Remove the screw and watch out for the spring hidden under the right hand side. (more on this spring later)

The spring in question is tiny, with a small metal piece which inserts into it. I couldn’t really take a suitable photograph of it so used my artistic skills (sorry there is a lack of that!) to draw it instead. This spring is what pushes the lamp module away from the casing as it travels up the worm drive.

Kent Wedding & Portrait Photographer

This spring is tiny. The drawing…not quite as well executed as the photos!

I didn’t find a need to remove any more of the screws from this point, the lamp module (with some more of that technical wiggling) came out of the white moulding.

Various wires are held in clips, so I released all of these to create more slack and allow me to get to the lamp.

Kent Wedding & Portrait Photographer

Three points require soldering. White ‘rubber band’ requires patience to remove and re-fit.

To get to both ends of the lamp, firstly you need to remove the black bracket located at one end. Again be careful as Canon’s clever engineering has created two, what appear to be, very random little pieces! (Stupidly, I didn’t think to photograph these!) They come in the form of a square piece of glass (approx 2mmx2mm) and a circular piece of foil (2mm in diameter) and sit inside the square bit of this black bracket. When re-assembling, the circle is on the bottom and the square goes on top. I have no idea what these parts do!

Kent Wedding & Portrait Photographer

Slowly remove this and take note of the circle and square that drop out of the top end.

Once you have unsoldered this end of the lamp, you should be able to get hold of the white ‘elastic band’ and stretch it across the freed end of the lamp and get access to the rest of the lamp to desolder and remove it. This stretchy white thing is really fiddly to deal with. It’s quite tough to stretch and I was constantly worried about snapping it. Simply take your time. It was in fact, putting this back on the new lamp, that was more worrying as I thought the tension at the wrong angle, could cause the new lamp to snap. I didn’t want to be back where I started!

Kent Wedding & Portrait Photographer

Desolder the other end of the bulb from the tiny circuit board

I have to be honest. I got carried away with solder fumes at this point and stopped taking photos. There weren’t really any left to take; the disassembly in reverse order!

I hope that all makes sense and was clear enough. As you can see, it really wasn’t difficult to do just fiddly. What you don’t see from these pictures is that I had the flash gun, all the littles parts and all the tools spread over most of my lounge floor. Due to a busy work schedule (starting the job when I really didn’t have time to) it remained in this state for about 3 weeks! I was grateful for the photos to remind me how it all went back together again! In total, it should have taken no more than one hour to mend.

I am now back to owning three working Speedlites 🙂

2013 Amendment…

In January 2013, ‘The Last Supper NYC‘ Dave contacted me regarding his spring frustrations. These were the few steps that I was so busy fumbling with that I didn’t actually photograph! Some discussions later and only once Dave successfully fixed his own speedlite, he kindly sent me his photographs to fill in some missing steps. Thanks Dave 🙂



22 Comments leave one →
  1. online forex trading permalink
    November 13, 2010 7:37 pm

    When I see a great blog post I do one of three thing:1.Forward it to my relevant it in all of the favorite social sharing sites.3.Be sure to visit the blog where I came accross the article.After reading this article I’m really considering doing all of the above…

  2. Nicolai permalink
    January 12, 2011 2:28 pm

    Hi, where did you get the tube from? I have the exact same problem, but the local repairshop won´t sell the tube as a sparepart.

  3. January 12, 2011 3:07 pm

    I was easily able to purchase the bulb from a Canon recommended servicer:
    This company were very helpful.
    Good Luck.

  4. Michael Fonseca permalink
    January 25, 2011 6:28 pm

    Great website. I just changed the bulb on my 550EX and could not have done it without this site to guide me through it. Got the spare directly from Canon for ~$12.

  5. January 25, 2011 6:52 pm

    Michael, So glad that you were able to fix your speedlite and that I, somehow (even in a small way) played a part.
    I’ll send you my invoice 🙂

  6. Reno permalink
    August 2, 2011 2:36 am

    I want to thank you also for this write up…I was given a 550EX flash that the photographer couldn’t figure out, and a bit of “surfing” led me here, and I was able to fix it with your guidance!!! Thanks!!!

  7. August 2, 2011 5:53 am

    So glad that you managed to find my site and that it was helpful to you. I keep waiting for something else to break now so that I can write another helpful blog like this one 🙂

  8. July 28, 2012 5:35 pm

    The flash works fine after following you guidelines. The only problem is the focusing doesn’t work. The little engine tries to readjust the focus but it keeps making a rattling noise and I can’t change the focus. I guess I have to readjust the position of the bulb head before putting it together. Any idea how to do this? There must be a default position for the bulb head….

  9. July 29, 2012 9:12 pm

    I did it! You have to put the white bulb head on the upper position and the flash engine will adjust it automatically once you power up the flash unit. Make sure that the cables let the bulb head move freely! It works awesome!!!

    • July 31, 2012 12:08 pm

      So sorry I didn’t get back to you. Life is pretty manic with working at the Olympics. So glad you figured it out yourself though, that’s often more rewarding. 🙂

  10. 50hzwurnSven permalink
    August 20, 2012 11:36 pm

    Great blog post! I like it. (: Currently I have the same problem with my 550EX.
    So I have a question: Which part did you finally installed? The 550EX flash tube (Y17-3159-000) or the tube from the 580EX?
    Thanks! 😀

    • August 21, 2012 5:42 pm

      Hi 50Hz 🙂
      Glad you like the blog and that it’s been useful to you.

      As I said in the blog, it was just the lamp (y17-3159-000) itself that I installed but that’s only because that’s how the part was available. The 580EX only has the entire lamp assembly to purchase. At the time (I don’t know if it’s different now) you couldn’t buy just the lamp itself for the 580EX and nor could you purchase the entire assembly for the 550EX. Either way, it’s not a difficult job, just fiddly and requires patience (and probably a steady hand).

      Let me know how you get on. 🙂


  11. thelastsuppernyc1 permalink
    January 15, 2013 2:25 am

    I do not know how to replace the tiny spring! Can you please shed some more light on the exact positioning before screwing everything back together. This has had me mind boggled for the last hour.

  12. January 15, 2013 9:06 am

    thelastsuppernyc1, my memory is somewhat faded on this subject now. I’m not sure exactly how the spring and plastic bit fit within the flash assembly. 😦

    I seem to remember that there is a squarish plastic block beneath the screw (by the left arrow on photo 9. I believe that this plastic block has a little dimple which the small plastic bit (see the drawing) sits within.
    My text says that this spring is “what pushes the lamp module away from the casing as it travels up the worm drive” so bear this in mind when working out the positioning of the spring.
    If you have any photographs that you can share with me, of inside your flash gun, then it may jog my memory more. The photographs featured in this blog are the only ones I have.
    If anyone else can leave advice regarding the spring, please feel free to share.

    You can also share photographs on my Facebook page:

    • thelastsuppernyc1 permalink
      January 15, 2013 4:18 pm

      Okay. I was hoping I didn’t have to squeeze the spring together. Let me see if I can figure it out and I’ll take some photos for future reference to those having similar issue anyway. Thanks for the response!

      • January 15, 2013 4:30 pm

        I do remember that the spring bit was very fiddly.
        Sorry that I wasn’t of more help.
        Good luck.
        Feel free to email me some photographs and I can upload them to the site for you (with credit, obviously!)
        Nikki 🙂

  13. thelastsuppernyc1 permalink
    January 15, 2013 6:08 pm

    I figured it out and I got some decent macro pictures for you. Soon as I piece everything back together I will email you the photos. Guess all it took was a good night sleep to approach the problem differently. Thanks so much.

    • January 15, 2013 6:26 pm

      Ta-Da! So pleased that it worked out for you. It can be pretty frustrating and fiddly, so probably best that you ‘slept on it’. Look forward to receiving your photographs. I’ll get them posted ASAP 🙂

      Now just make sure you put it all back together correctly without having one ‘mystery’ screw left over 😀 (engineering joke!)

  14. May 19, 2013 11:28 pm

    Hi There
    Youre’ article was very helpful to me although i went about it in a bit of a different way. i broke the tube in my 550ex and decided to try and replace it with a part from a broken 540ez i had, on inspection found that the flash tube reflector etc looked virtuality identical apart from the little optical sensor at the front of the fresnel. i unplugged the flash assembly and pulled the optical black wire out from its position (tricky to feed it out through the rotating part of the flash, just replaced the whole part put it back together and it works great so if you have a broken flash tube in a 550ex try picking up a 540ez in good nick and do the swop, saves having to do any soldering

  15. Andy permalink
    July 14, 2014 2:22 pm

    Thought this might be of interest ))

  16. July 27, 2015 11:48 am

    I didn’t do this til the flash was disassembled and ended up getting a nasty …

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