Sunday, October 12, 2008

Neutering a Nikon SB-20

As I've said many times, I think the Nikon SB-20 is the best used flash deal out there. How else can you get a reliable, powerful shoe-mount flash with manual and auto modes for $30?

In my SB-20 review I mentioned that I neutered my first SB20 to allow me to use it on my Canon camera. This post is a picture-heavy walk through of how I executed this (really easy) modification on my second flash. It doesn't damage the unit at all and allows you to safely mount it in any hotshoe without worries of malfunction or damage.

To start, here's my victim... ahem... my SB-20:

Note the four pins on the bottom of the foot (hotfoot?) shown in more detail here:
The center pin is the standard flash trigger which any hot shoe short to the base connection to cause the flash to fire. The outside pins are for TTL control and other fancy camera functions with acronyms. Since I have a Canon, and the SB-20 TTL only works with Nikon film cameras, those outside pins aren't needed and I'll be disabling them. If I left them in, the flash may malfunction or cause damage if mounted on a non-Nikon camera.

For the record, I don't know if any damage would result for sure (actually, I doubt it), but I like to play it safe with these things. The good news is the pins are easy to remove and replace, so it'd be easy to add the pins back if I sold it again.

Standard Disclaimer: Shoe-mount flashes contain high voltage capacitors which maintain their charge for a long period of time (possibly days). If you've used the flash in the past few days, dump the charge by triggering a full-manual flash and immediately turning off the unit before it recharges. That said, you should be nowhere near the capacitor for this mod and it is about as safe (and easy) as they get.

The first step is to remove the bottom plate by unscrewing the four attachment screws (visible in the picture above):
Use a small Phillips-head screwdriver for this task to avoid damaging the screws. Yes, I know I'm using a flat head screwdriver -- do as I say, not as I do.

Once done, the bottom plate should easily tilt off as shown:

Carefully pull the plate out to expose the wiring harness:

And gently disconnect the white connector (it is pretty tight, so you might need to wiggle it to get it to slide out):
Now, see those three screws in the image above on the circuit board? Unscrew them and set them aside. Note those screws are a little longer than the four that hold the base on -- don't get them confused!

Removing those three screws will allow the foot to pop off (don't try to pull the circuit board out -- the springs get in the way!) exposing the pins floating on springs:

Remove the three outside pins from their springs. The end of the pin fits into the spring by friction, so pull gently and give them a twist and they should come off pretty easily. The result is this:

Here's more detail, with the unmounted pins sitting to the side:

And really, that's it. All you need to do now is reassemble it in the reverse order. You'll want to stow the pins in a safe place. I just wrapped mine in a non-conducting package and jammed them in a space near the back circuit board (see white packaged near the bottom of the unit below):

When completed, the foot looks like this:

And the modified Nikon SB-20 works on any camera and in any hot shoe you'd like to use!

3 comments:

David Wong said...

I always wondered how you removed those pins from your first article, thanks for posting this "pictorial", I just performed my own little surgery, and it works like a charm!
Thanks!

Sean said...

Glad to help, David!

Andre Reinders said...

I just followed your instructions, and all went well. Thank you very much!