Few days back I was planning something quite different but ended up fixing a broken Sega Saturn 3D Control Pad – the analog variant of Saturn controller that came bundled with Nights into Dreams.
The magnet (circled in yellow) should not be here, but insidethe other trigger’s plastic cradle
This one was only slightly broken. It was otherwise ok, but the other analog trigger did not response at all. I remember opening it up in the past, but now that I took second look inside I realized what was wrong.
The magnet. It had fallen off from its socket and attached itself to the other trigger’s magnet.
Unlike just about any other controller with analog functions, this controller is making use of magnetic sensors instead of the usual potentiometers. There are sensors that measure changes in the magnetic field as magnets move closer and away. Both the analog triggers and the “3D” pad work this way. The advantage of this is probably that they don’t wear over time as there is no mechanical strain to the sensors itself. The much similar Dreamcast controller uses this same principle.
So fixing this pad was as simple as putting the loose magnet back to its socket.
Update (22nd July 2019): These magnets need to be facing the right direction – check details posted in comments by retron8.
ilesj's blog 
I really appreciate people who forward information like this online. This is exactly what befell my 3d controller yesterday, while playing a pinball game – I lost responsiveness on the shoulder controller trigger on one side, and suddenly heard something rattling inside. So I unscrewed it and out popped a mysterious magnet, origin unknown. Thanks to your posting, I now understand where it’s come from and it should be easy to fix. Thanks!
Glad to hear this post was helpful – I hope you got your pad working again. Cheers!
Thank you for posting this. Exact thing happened to my 3d controller and it’s really a simple fix once you know what’s wrong.
How do you get the trigger out? and how do you get the magnet to stay in place? mine keeps falling out
There are those tabs at the sides of the trigger that are holding the gray trigger in the white frame. You can see the tab right between my thumb and index finger in the last picture. Push the tabs carefully while prying out the trigger should release it. If it is not necessary to remove the trigger from the cradle to get the magnet back to its cradle it may be better not to.
If the magnet keeps getting loose, you can fix it into the trigger’s cradle by e.g. by using glue. That should not affect to the way how the trigger sensor works.
An odd question, but I’m having trouble getting the screws off the controller so that I can tinker with it. Any tips or thoughts on decent screwdrivers would be most welcome! Kiitos teille.
Hello. Sorry, your message was in spam and I didn’t notice it until now. The screws on the Saturn 3D controller are small cruciform types, Phillips tip size PH.1. Given the small size of the screws and the fact that they can be quite stiff when unscrewing for the first time, it’s important to have a correct type of screwdriver. Especially do not use slot type or flat head screwdriver, or a Phillips type that is too big. Otherwise there’s a high risk that you cam out the screws. If that happens, it will be very difficult to unscrew them.
I got a Sega Saturn recently and bought a 3D pad soon after, but I also discovered that the triggers don’t work. I unscrewed the pad and also had one magnet attached to another one. I placed it back to its original position but the triggers still don’t work. I checked the magnets again after that but they were still ok.
Any ideas what could be wrong? Could the loose magnet have damaged both triggers or might there still be a solution?
Hi – I doubt that the loose magnet could have damaged the sensors. Could it be a compatibility issue? The pad has a switch to select between digital (works as a normal controller, the “+”-symbol) and analog mode (circle). Not all games support the analog mode. See the list of supported games for example at http://segaretro.org/3D_Control_Pad
If the triggers don’t work even in the digital mode as on/off triggers, then there’s some issue with the pad or trigger sensors.
Thanks for the fast reply. I’ve tried it with Nights into Dreams and with Panzer Dragoon Saga, I’ve checked the compatibility before I bought the games. The triggers didn’t work for these games, i’ve tried both the digital and analog settings, the switch works (thumbstick only works in analog mode), so that isn’t the problem either.
Hmm. Are both of the triggers dead? Can you check that the ribbon cables that connect the triggers to the logic board don’t have any wires broken? From what I understand on how the 3D pad works, broken connector or controller cable would render also the analog pad nonoperational.
Maybe a silly question, but when in digital mode, does directional pad “right” and start work? No problems with normal game pads?
Hey, I just ran into this problem and I discovered that you need to have the magnet facing the correct direction for it to work. The polarity is marked with a dab of white paint (on mine at least), and it only consistently worked once I got it pointing the correct direction.
Thank you for putting this up here! I did try fixing both my 3d pads, but the magnets never seemed to stick. I tried using super glue, and now the trigger doesn’t work at all! It’s ok, I will just use them for games that don’t require the L and R triggers, at least until I can get new ones. Still my favorite controller of all time!
Hmm, that makes me wonder if the sensors are polarity sensitive. It’s weird if these triggers just stop working. Have you tried flipping the magnets the other way around in their sockets?
No, I haven’t tried that, but I will, if I can get the glue undone without breaking them further!
The sensor totally are polarity sensitive! I just confirmed it on my pad.
Hey! Thanks for the additional info. Seems that I got mine correct on the first try by luck :) I posted an update in the article about the polarity.
I’m having troubles re-assembling the thumbstick on this controller, that spring is being very annoying. I took it apart to clean it and it just wont go back together, can anyone help me figure this out? Thanks
This happened to my left trigger. I found the magnet stuck on the pcb board and realized what it was. I put it back in the trigger, but I must have had the wrong side facing the sensors, because it still doesn’t work. Now i need to pop the magnet out somehow, and flip it around. Hopefully this works.
I’m certain you’ve probably solved this already, but if you stick a pin up through the other side you can dislodge the magnet and flip it around so that it’s facing the correct direction.
Thank you so much, I was able to repair my Nights pad thanks to you