Carl Hutzler's Blog

Whoever created the camera flash PC type connector was not an engineer. PC Cord connectors (especially the female side) are very unreliable (hmmm, likely a joke in there somewhere). This is especially problematic for professional photographers who expect their equipment to never fail. One major flaw of the PC connector is that the center connector on the female end is a “split ring” which after a number of uses (plug in, unplug, rinse and repeat) tends to get bent out of shape and tolerance. So the male end does not make good contact any longer. Add in some corrosion from oxidation, etc, and you have guaranteed failure at some point.

Why do SLR camera manufacturers continue to use these instead of something better? I don’t know. Maybe the PC connector is a standard and people expect it. Maybe the people who sell cables for 100x their cost which fail regularly have control? Maybe the connector is a very “low profile” connector making it easy for camera manufacturers to integrate into their camera bodies? Whatever the reason, they stink.

One thing I have noticed, though, is that professional flash systems (big studio strobes) mostly use other types of connectors – either a standard 3.5mm headphone jack (just like your iPod) or what looks like a two prong 120V AC plug (of course, you don’t plug AC into it!).

Recently I bought into a wireless flash sync system called PocketWizard. These are transmitters and receivers (and the newer transcievers) that use RF signals to trigger off-camera flashes. You mount a transmitter on the camera’s hot shoe and the receiver units are connected via cable directly to the flash units. Receiver and flash can be located up to 1500 feet away from the camera/transmitter!

Anyway, the pocketwizard receiver units connect to the flash units via a cord (no magic there). They give you a cord in the pocketwizard receiver box which has a 3.5mm connector on one end which goes into the Pocketwizard and the dreaded PC connector on the other for your flash unit. I used these for a while to connect to the PC connector on my Nikon SB-25 flashes. But one after the other, I found the flashes would start to become unreliable. I wondered if I could yank the PC connector out of the SB-25 Flash and replace it with a 3.5mm headphone plug….turns out not only can you, but it is not really that hard!

What follows below is a step-by-step approach to accomplishing this feat. But a couple of warnings are in order:

1) Taking apart your flash unit is your responsibility. You will void your warranty (if you have one). It may be hard to get it back together. It may not work when you put it back together. I take no responsibility for what you do if you choose to attempt to take your flash apart.

2) Flash units take lowly 1.5 volt AA batteries, but inside the flash unit, the electronics increase this voltage 1000’s of times. This means that certain circuits inside the flash can have very high voltages and can be dangerous to your health. In addition, flashes have circuits called capacitors that store this high voltage energy. These capacitors can store a charge for weeks after the flash unit is turned off and powered down. Assume there is stored charge inside and be careful! I take no responsibility if you kill yourself doing this. Know what you are doing or don’t even consider taking your flash apart.

3) I have only tried this with an Nikon SB-25 flash. Other flash units may also work, but keep in mind, your mileage may vary.

With that said and everyone trembling in your boots, its not that hard of a process if you know how to take things apart and put them back together and can use a soldering iron.

What you will need:

1. Soldering Iron
2. Small phillips and flathead screwdriver (jewelers type works well)
3. Small pliers…needle nose works well
4. Small wirecutters
5. Some small diameter wire (unless you are skilled enough to reuse what is already there)
6. A Nikon SB-25 Flash (other similar flashes may also work – no guarantees)
7. Perhaps most important, a 3.5mm headphone jack (female). Try and find a low profile one that does not extend too far in the back. There is room inside the flash, but not a lot.

This is what you are going to try and do. Put the 3.5mm headphone jack inside the flash in place of the PC Connector.

The SB-25 flash comes apart in halves. There are 4 screws on the top, two on each side. In order to see them, you have to rotate the flash head 90 degrees one way or the other and be sure the flash head is pointed up (like you are doing bounce flash off of the ceiling). You can remove all four screws if you like, but you don’t need to and it makes reassembly a bit harder. I recommend removing one screw from each side on the SAME half of the flash.

Next up are the four screws on the bottom of the flash where the camera hot shoe is located. Remove all four. At this point you should be able to gently slide the flash apart.

You only need to slide it apart a little ways, enough to get access to the PC Connector area like below. The battery door may come off…no big deal, just don’t lose it. Remember that there are things inside the flash that retain electric charge and are very high voltage. I recommend not taking the flash apart further than you need to.

The PC Cord connector is part of a dual connector assembly. The other connector might be some sort of Nikon TTL system (I am not 100% sure). Anyway, both of these connectors are connected to the flash via a connector which can be removed by gently prying it up with a small flathead screwdriver. The picture below shows the successful removal of the dual connector assembly and the battery door which typically falls off in the process.

The back of the PC Connector (on the right) has two wires. The Nikon TTL connector on the left (if that’s what it is called) has three.

Cut the Blue and Orange wires on the PC Connector – both the ones coming from the TTL plug and the ones coming from the red 3-wire connector. Leave as much of the wire intact as possible. If you are really good, you can reuse the wires when you install the 3.5mm jack. But if they break off in the processing or are not quite long enough, just use some new wire. Either way.

Remove the PC Connector by loosening the nut on the back. This may take a wrench or needle nose pliers. But it does come off. Once the nut is off, you can remove the PC Connector. Now try fitting the new 3.5mm headphone jack. It may need a little filing or dremeling to fit just right. You may also need a washer of the right side to get it to be secure in its new home. But this is usually not that hard if you bought a jack that is fairly close in size. Radio Shack is your friend.

Solder the wires back up. Keep the wire placement the same as before. The orange one is the center connector and the blue is the side/ground connector. If you are not sure which contact is center and which is the side on the 3.5mm jack, an ohm meter will help or careful inspection will tell you. Hint – the protuding piece of metal on the back makes contact with the center post of the headphone jack.

Time to put it back together and see if it works. Reconnect the (new) 3.5 headphone and TTL connector assembly to the flash by reconnecting the red 3 wire connector. Gently push the two halves of the flash together and remember to put the battery door back in its place. It can help to rotate the flash head a little as you press the halves back together. Once the halves are together, secure the two screws with the flash head rotated 90 degrees. Lastly, replace the flash hot shoe on the bottom of the flash with the four screws it takes. Then insert batteries and see if the flash powers up. Try a manual flash by pressing the test button. If all looks well, attach a dual 3.5mm headphone cord to the flash. Use a penny or screwdriver to short (connect) the other end of the 3.5mm jack and see if your flash fires. If it does, all is likely well. If not, well, take it apart and see what might be wrong.

Now you can use any standard 3.5mm cord, readily available at Radio Shack or the one that comes with your computer’s speakers, etc. to connect your flash to your PocketWizard. Stereo or Mono should both work as long as its the same connector on both ends. As an added bonus, you can put the flash on your camera’s hot shoe and connect it to a pocketwizard transmitter. This combination gives you an on-camera flash which triggers other remote flashes that have pocketwizard receivers (nice for weddings and other stuff).

A couple of helpful things:

1) On one of my three SB-25 units, I put it back together after all of this and it would not turn on. Took it back apart and found that when I tightened down the new 3.5mm jack, I inadvertently pushed the contact points of the jack together so they were shorting. I separated them and all was well. So just in case this happens to you, you know one thing to look for/be careful of.

2) If you reverse the orange and blue wires (center and side connectors) by mistake, when you put it back together it will still work as a normal flash slave. But the flash will not work properly in all cases, especially where you want to use the flash on-camera and have it trigger a remote flash via the pocketwizard transmitter. So do it right the first time :-)

Happy flashing and be sure to check out Strobist, the best “small off-camera flash” site anywhere. This is where I got this idea in the first place!