As you know, I have battled the speedlight before. And been hopelessly crushed. I literally broke it apart to sell as scrap, and purchased a used Canon 550EX. This weekend however, I dropped my camera, and the flash hotshoe snapped. This is an “easy” replacement, and the part is only around $12 from ebay. However, since I have the 420ex parts around… might as well use them.

I followed the instructions here on DP REVIEW and they were pretty good. As I started searching around, I also found two visual tutorials that look good:

I only have 1 or two things to add to the above tutorials. I’m going to assume you managed to disassemble the hotshoe, and in the process of putting it back together with your replacement piece.


Both DP review and Neil VN talk about this step, but it didn’t make sense to me:

Screw the locking ring back on. I would HIGHLY recommend having the locking ring in the “LOCKED” (screwed all the way on) position to get it lined up for the re-assembly (if you have it some other place it is possible, take my word for it, to assemble everything and find out that the locking pin will not work).

The lock ring rotates to clamp your flash onto your camera. If it is too tight or too loose, when you reassemble it, it won’t clamp correctly. So what you should do is rotate it until it is “locked”, before you reassemble. I had no idea which direction this was, so I confirmed I had it correctly by sliding the hotshoe in place, putting in one screw, and then testing it out on my camera.

You will know you have done it correctly, because it locks in place.



in the DP review tutorial:

2. You have to remove the 2 screws holding the on-off switch to get at 2 of the screws the hold the foot (the other two screws are accessible). You don’t have to remove the light as there are no screws under it (how would I know that?). The slider for the switch and a plate with a red mark will come loose. It is good idea to note how they fit.

I took a photo of it, and that didn’t tell me what I needed to know later. So here you will need this. When you are putting it back together, this is the order those pieces go in.



I had to use several different screwdrivers on this project. I wish I could offer advice on which ones to have in advance. but I dont. they are all “small phillips head”, but some don’t allow for much depth, and I almost stripped the hell out of one before I realized it wasn’t turning. And a rubber pad for opening tough jars is a must-have for this type of thing.


Time tooken: 1 hour (-5)
Screws lost: 1 (-5)
Small springs lost: 1 (-5 )
Working: Hell yeah. (+20 )


Overall a pretty easy fix. Only real barrier is lack of attention, losing screws and the like.






Right. So in Last weeks BATTLE SPEEDLITE 420EX I lucked into a victory. Basically after taking apart, and half reassembling a broken flash.. I put the flash on my camera, and it still wouldn’t fire. I rotated the head of the flash around a bit, heard a noise, and suddenly the wonderful whine of the capacitor charging up. Because the flash was partially taken apart, I went back to my workshop, and finished up with the assembly.

I was disappointed when, on returning with my “new” reassembled flash… it would not work.


Part 1: “Well, what next.”

I’m not sure why the flash doesn’t work. I don’t clearly remember if I did hear a “crunch” before the flash fired. I am cast adrift in an ocean of “what the fuck do i do now”.

Ok – lets take stock.

  • Power is getting to parts of the flash. For example, when I power the flash up, this happens:VIDEO
  • I no longer hear the whine of the Capacitor inside charging up.

I guess I could trace the power inside the device, and see if it is making it to the capacitor!

Part 2: Strip it down

Because I don’t really know where to start “tracing the power inside the device” ( I just sort of made that shit up ), but I DO know how to take screws out of things… So why not do that!

I pull out the screws I know and end up with something that looks like this:


Now, as you might have read from last time, messing around with a photography capacitor is a great way to get shocked. something like 300+V could be sitting in that thing. The instructions want me to pull off the rubber caps on the side of the Speedlite Flash Head, and this will let me access enough of the cap to safely discharge it. They are a pain to get off, and are actually glued on. I used a screwdriver to dig under the edge, scratching the shit out of everything, but finally getting a good enough grip to peel it off.

IMG_8526 IMG_8527

Part 3: Defrazzle the Frozzle

There are a number of ways to drain a capacitor. Apparently some people like to bridge the poles with a screwdriver. This makes sparks and I guess sometimes gouges pits out of metal. While, this sounds fun and all, it isn’t really an option. I can barely get to the poles. I have to put together this fuckery, which I attach to a resistor. It isn’t the right resistor to be using – this is 50w 8Ohm, and is used as a dummy load for audio amplifiers. But whatever, I’m in a hurry. And I’m pretty confident I’m not going to see much voltage going to the cap ( since It isn’t even charging up to begin with ) .


Draining the Capacitor

I wasn’t sure that I was actually connecting to the cap, because of how this works – you have to shove a thin wire down into the body of the flash to touch the positive pole of the cap. To confirm this was connecting – I set my Multimeter to “continuity”.. basically this sends a small charge across, and if the connection is good enough, it “beeps”.

What happened instead was I saw the resistance increasing, and then flip to a “1”. No connection. I seem to recall that this is what happens when you try to check resistance on a capacitor. Basically your multimeter is sending out a small charge to check continuity.. but the cap just eats it up. as the cap starts to charge up, resistance increases, until to goes to infinity ( 1 ) .

Sure enough when I now check the voltage on the cap – I see a small charge. This tells me I am successfully draining, and charging the cap. So I drain it again with the 8 ohm 50w resistor, and get back to work.


Part 4: Shit’s still broken

I’m going to sum up the next two hours pretty quickly here.

  • Small screws
  • Spring shoots out when you take off top of the flash
  • Attempt to measure if the Cap is good, but my tester is the wrong range AND you can’t really measure a cap while it is in the circuit. ( 1 hour wasted right fucking there )
  • I try to read an electrical schematic, all i get out of it is that the Cap is 1150uF/330V
  • Frustrated, I am going to end the day by just putting it back together.
  • Another goddamn spring shoots out.
  • I find  a wire that has pulled out. Momentary joy as I think this might be “the problem”.
  • Solder that wire back on. accidentally de-solder the wire next to it. May or May not have soldered the shit out of the plastic LED that the wire attached to ( AF ASSIST BEAM EMITTER )
  • Put flash back together – only 3 screws left over! I know where 1 should have gone, but I made 2 extra screws appear.. clearly we have some Loaves and Fishes shit going on.


get some nice sharp/small testers

get some nice sharp/small testers



soldering These 3rd Hands really kick ass


Final for the day:

  • Still powers up, but no charge to cap that I can see
  • Try to test the lights on the front. I can get the left of the 2 front red lights to turn on ( I think one is a wireless indicator ) .So basically nothing gained today. Part DEUX definitely goes to the broken flash. All I accomplished was to hit on yet another series of personal limitations, and possibly wrecked the AF Assist in the process.

Dark Days Ahead.



BATTLE SPEEDLITE! PART UNO ( Speedlite 420EX Camera Flash )


Because I don’t have enough hobbies, and because apparently shopping for things is more fun than actually using them, I have taken up PHOTOGRAPHY! And because I am cheap, and hesitant about spending money, I limit my impulse spending to “great deals” and stuff I can “surely fix even if it IS broken”…

I purchased a first generation DSLR with some accessories at an auction. Enter the 420EX flash – surely a GREAT deal, until I got it home and it won’t power up.

STEP 1: Test the obvious shit

Step 2: Tool time!

Using my multimeter, I tested the batteries ( you know, just in case ). Placed the 4 batteries into the Speedlite Flash, and then checked to see if power was flowing between the two pairs of batteries. It was not. This suggested to me that there might be a broken connection inside the camera – I was pretty happy about this, because I can solder shit. A physically broken ( or corroded ) connection is probably in the realm of things I can fix.

Please ignore the voltage readings you see here. This is what I did, but the first time I did not get these readings.


Step 3: Breaking it Down

Started taking out screws, took me a while to find them all. 4 are hidden on the top of the flash, and you have to rotate it 90 degrees to see them. I very quickly stripped that top screw, but the others came out nicely.

IMG_8237-800My goal was to get inside, check the continuity of the battery connections, and hopefully narrow down the problem. When I opened it up nothing major fell out… but this time when I checked the voltage on the batteries… I got nice readings ( see top picture for reals this time ).

HEY I FIXED IT, I naively thought. Perhaps some wires were twisted, and I magically untwisted them, and lets go play with my new flash. I tried to put it back together again, and ran into these two little issues:



That thin plastic is supposed to slide between the board and the rotating part of the flash. For the life of me couldn’t get it back in. So I took it out. I’m guessing it might be important, but for now I don’t care.


To get the two halves back together I had to push down the rotate button on the back of the flash.. this raises a pin, and allows the pieces to snap back in place. It is conveniently labelled “PUSH”.

IMG_8232-800 IMG_8233-800

I didn’t put all the screws back in – just once screw in the bottom so the whole thing wouldn’t fall apart while I was holding it.


While the Speedlite 420EX flash would not power up on it’s own, I thought perhaps that this flash might only work on the camera. why? who knows, but I was feeling hopeful.

I went and plugged it on my camera, and of course nothing happened. Frustrated, about this time is when I actually READ the user manual I downloaded… looking for some secret answer to my problem. Perhaps there was just a switch I was missing.

It is worth noting that I took the entire thing apart, risked breaking it, and wasted a bunch of time BEFORE I even read the fucking manual. This is why I am pretty terrible at fixing things, and why every single victory in this blog is not just a victory against some horrible broken piece of trash, but against my own innate inability to Measure Twice and Cut Once.

So I RTFM’d and set all the switches, and nothing changed. Since I’m now in RTFM mode, I decide to download the SERVICE MANUAL and give it a read. Something important to note here… I could have really shocked the shit out myself. There is a capacitor that needs to be drained before working on this flash. And I guess there are like up to 100 volts that can sit around in it and shock the shit out of you.

So I learned a bit, and was preparing to go tear this thing apart again… but while playing with the rotation of the flash, suddenly it powered up. There may or mayn’t have been a crunching noise as it turned and then energized with an awesome whine.

Now the flash is not fully put together yet, so some wires are loosely held in place, and my initial thought is that some wire must have been pinched, or there was a short, or something that my monkey like banging has fixed. Not the most noble victory, but I’ll take it.

Tomorrow.. the exciting conclusion to BATTLE SPEEDLITE 420EX!