EOS R6 teardown reveals the timer chip that’s holding the camera back

The wiring diagram for the RX8130 looks like this, page 7. I was able to identify the clock battery feeds into pin 10 through a 470 ohm resister. Pin 7 also connects to ground. Interestingly, pin 6, 2, and 3 either connect to nothing, or connect to something directly going down under the board. We need to remove the chip to see more definitively, but potentially they are not used.

Pin 4 from the documentation is used for the frequency out, and this connects to a 6 pin chip immediately to the right that reads only pQ on it, hopefully someone has more insight on this chip. Pin 5 leads elsewhere on the board we can’t identify. Pins 1 connects to a distant BGA mounted chip with what looks like a smoothing capacitor connection to ground. Pins 8 and 9 also connect elsewhere we can’t trace yet and also feature smoothing capacitors.

So far, that’s all the progress we made. We like to be transparent in what our mods do, so we decided to open up our research here as we go. Based on this chip’s documentation, our basic understanding is that this chip receives power from the main board first, and if there is no power there, it draws power from the backup button cell battery. The chip is able to keep time, and can output time data, as well as other stored data, there is some room for general bit storage. The chip is also able to send interrupt and data signals back out, but so far it doesn’t look like those pins are necessarily being used. Canon may not be using the internal interrupt and timer functions, and may be doing that elsewhere using this chip as only a timekeeper.

Our next plan is to verify this with an R5, and pop the chip out and see if we can measure any signals on a scope during the actual overheat event. In the meantime, from how the settings storage is handled, it looks like we should be able to just remove the clock battery, or put the clock battery on a separate toggle switch. Also, we can of course bypass the hard reset screw approach Andrew Reid did, and just put a hard switch on the power leads to the main board. We can even control these switch with a microcontroller and force a hard reset through software if needed, say something like, after you hit record the camera cycles a hard shutdown after 15 minutes, or cycles an ordered shutdown paired with a clock reset as a coordinated event. We also want to check how the camera behaves if there is no clock power even when the camera is on. I suspect a hard error, but who knows! BUT WE NEED AN R5 to start. Please, internet. If you have one you can loan or sell us, we’ll share what we find publicly and give you first access to our Frankenstein bypassed ultimate R5 mod.

Also, one important comment. While it seems definitive that Canon is using a timer circuit to shut down the R5 in overheating, we can only speculate as to why for now. It is possible that it is just to cripple the camera, but it’s still very possible that there is still some overheating concerns for this weather sealed body, and they are shutting down based on a timer schedule for now for longevity. I would approach any of these bypass strategies with extreme caution, as they will probably not only void your warranty, but potentially fry your camera from extended shooting. We still plan to open up the R5 and add a heatsink that’s thermally fused to the overheating chips and card slots, and attach this heatsink to an aluminum cage for dissipation, as well an active fan. In this cooled context, we expect to keep the R5 very cool for extended shooting, but it would require the timer shutdown to be bypassed.

So let us know what you think and if you have any chip insight! What would you like us to try next?

About the Author

Ilija Melentijevic is the founder of Kolari Vision, an infrared camera conversion business based out of Raritan, New Jersey. You can find out more about the company on its website and follow Kolari Vision on Facebook and Twitter. This article was also published here and shared with permission.