Canon EOS 650D (T4i) SD Card Repair


The SD card slot had become unreliable on a friend’s 650D and was giving a “no media” error message. At first I had just packed one side of the SD card with a piece of paper, which worked a couple of times but actually ended up damaging the pins more. The following photos show how I dismantled and repaired the camera.

Tools required:
– Small Phillips screw driver
– Small Torx screw driver
– Tweezers


  • Remove the 4 Torx screws under the grip


  • Remove the view finder cover and the two Phillips screws


  • Remove the two Phillips screws on the other grip


  • Remove the 4 Phillips screws along the base of the camera, closest to the screen.


  • Prise open the camera back from top to bottom, taking care for the ribbon and screen cable at the bottom.


  • The camera motherboard is now revealed. The SD card slot is on the bottom right corner on the under side. There are 5 Phillips screws to remove before you can take out the motherboard. One of them is covered by the plastic around the zoom button, but you can only just bend it out of the way to get the screw in the top right hand corner.


This is a good education in ribbon cable connectors as there’s a few different kinds. Most just have a brown flick up cable lock.

  • After removing the motherboard I could inspect the SD card slot properly and see just how damaged the pins were. I used a minimally destructive approach and cut the metal box slightly, so I could get tweezers in there to bend the pins. One of them was twisted but could be twisted back. Another one snapped off at the end, so I had to bend a new contact point. When you are doing this you really need to test with a card and be sure the pins are low enough to make contact, but high and bent enough to not get stuck on the underside!


In the above image, the SD card “Write Protect” detect is inside the RHS of the socket. Do yourself a favour and bend it in to shape the first time so you don’t have to re-open the camera. It should theoretically be possible to bridge two pins on the connector to completely bypass write protect, but I didn’t manage to reason exactly which ones so thankfully bending the pins was sufficient.


After reassembling, testing, and going round the loop of taking the camera apart again, I finally got it working again 🙂



Camera does not power on

This happened the first time I reassembled it. The camera will not power on if either the battery or SD card compartments are open.

Lots of videos suggest: powering off, removing battery and SD card and lens, then reattaching, inserting a battery but not SD card, closing all compartments, power on again. This didn’t work for me.

Another suggestion was to power off and remove battery, then switch to ‘P’ mode, power on camera and hold down shutter for 15 seconds. Don’t know if this helped.

What worked for me: Remove the internal battery momentarily after reinstalling the motherboard! This seems to reset the camera firmware in some way, and it will just ask for the timezone on first boot.

SD Card Write Protect stuck on

Once I finally had the camera powering on again, I was getting the ‘write protect’ error. I was able to resolve this by reopening the camera, and bending the pins on the right protect detect switch on the side of the SD card slot. I believe that when the switch makes contact, Write Protect is disabled.

SD Card not detected

This was the original problem. I should never have tried to fix the pins without taking the camera apart, it only weakened them. Dismantling the camera isn’t hard and I should have just done that first time.

USB NES controller using a keyboard brain

This is a little thing I made while procrastinating recently, it is similar to what I did with the controls on my first arcade machine – ripped a keyboard apart and wired the matrix up to switches. This time I used a USB keyboard and tried to put it all inside a NES controller. I have seen NES controllers being recycled all over the show so this isn’t really anything new, although using a generic USB keyboard means it works with Linux, Windows and Mac. I used the linux command “showkey” and a lot of trial and error to probe around and find the correct combinations to produce up down etc.

Making a Nintendo DS charger from a USB cable

I have just acquired a Nintendo DS original. It didn’t come with a charger but after inspecting the charger socket on the DS it looks very similar to a USB cable, enough so to fit a modified one!

  • I salvaged the end of a USB cable which I had cut up for something else. I used a male but a female could work with a bit of modification. The USB male is slightly wider than the socket on the DS so I cut off half of the shielding using small pliers:

    DS charger plug made from USB



  • As stated on the bottom of the DS, it requires 5.2V DC. I had a recently slaughtered Sanyo phone charger which puts out 5V DC which I decided to use. One could just as easily use the 5V from a USB port.
  • The USB cable I had was already cut in half, showing the familiar Red, Green, White and Black wires. The +ve and-ve terminals are reversed on the DS – the Red wire goes to the Negative and the Black wire goes to the Positive from the phone charger in my case. I just cut the rest of the wires short.
  • This is the final product!


    As you can see from the orange LED, it’s charging my DS splendidly.