Rebel t3 has fully Charged battery, but won't turn on....any suggestions?

[Chatty94]

I have tried two fully charged batteries, but my rebel t3 won't turn on.....it is about 4 years old....it has not been dropped or damaged....and I used it about 3-4 weeks ago with no problem. Any suggestions?

I did read in the manual that there are two different batteries......I have no idea where the second one is located or even how big it is.....

[nekfilms]

evanphilipps - thanks so much for your post describing a way to solve the T3i malfunction with a fully charged battery!!!!

I formatted my SD 128GB card using my MacBook Pro, popped the SD card in my T3i, turned the switch to "On" and

cautiously openned the screen - and voila! - works fine!!!

[BurnUnit]

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@John_ wrote:

...I would buy a can of Deoxit 5 or the small bottle of it and use that to clean off the internal contacts...

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Deoxit 5 is a truly miraculous elixir, isn't it?

[John_]

Deoxit 5 cannot be beaten!

[AnitaR]

Unfortunately mine is still not turning on. I haven't switch cards to another camera or anything - I even put in a new battery and a new card. Still dead. 😞

[John_]

What have you tried so far?

[7dprofit]

Try switching memory card. I find that if i have certain types of files on the sd card the camera doesnt fully turn on. Ive found that if i also use the sd card in other camera types as well that issue happens

[7dprofit]

Does the little red light at the lower right blinks at all when you switch on

[MOPF]

For me, the solution was simply to re-format my SD card! When batteries didn't work, I purchased a wall adapter to bypass the battery, but when the camera behaved exactly as the apparently charged batteries did, I did what I didn't think of before - I used my electrical tester to test the batteries and adapter and realized it was not the power supply (my existing batteries had been fine and my brand new new AC adapter (from B&H, NY, NY) had the same basic voltage and was also fine). Your hypothesis of addressing media storage led me to the solution. The camera had been dormant for possibly 2-4 months and when I put the SD card into my computer (Windows 10 OS) card slot, it signaled a memory device problem, so I reformatted it (exFAT appeared the only choice). Thank you. By the way, I still use a microSD in the SD adapter, but see that MAYBE I should go to an SD card, as some folks think the microSDs are problematic. I'm skeptical of that being insurmountable, but am grateful for the redflag and will be mindful of that as an impending data-loss disaster. 

[BurnUnit]

Hence the recommendation to always perform a low-level format on any SD card the first time you use it in any given camera.

The problem with using a micro SD card with an adapter seems to be that it introduces an additional set of teeny, tiny electrical contacts into the circuitry between the memory card and the camera. Just one more place for a potential failure.