# Constantly flashing read/access light on 5D3



## timkbryant (Feb 18, 2013)

A few days ago I dropped my 5D3 from about 6 inches.

When I turned it on, the read/access light (you know the red one) wouldn't stop flashing. Well, it wouldn't stop flashing when the CF card slot was selected.

I tried turning the camera off and back on again. Nothing.

Same for taking the CF card out and putting it back in.

Same still for choosing the SD slot, doing on-off, and then choosing the CF slot again.

So, in the end I backed up my photos and reformatted the CF card.

THAT stopped the flashing. And it hasn't flashed again since, except for the times it does in normal usage.

But my question is — anyone have any idea why the light would have been flashing constantly? It didn't change anything w.r.t. functionality, i.e. the camera still took photos and could write to the card. The light simply kept flashing.

I tried researching the problem online and came up empty. The manual is equally useless.

Anyone?


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## Menace (Feb 18, 2013)

The only occasion it happened to me was when I took out the SD card, put it in my wife's laptop to transfer the images and then SD card went back into the camera. 

When I turned the camera on, the red light was on for a long time. I turned the camera off and then on again and everything was fine.

Never happened since. Mind you I do not normally take the SD card out as i only use it as back up Jpgs.

Have you spoken to Canon?

Cheers


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## J.R. (Feb 18, 2013)

Its normal behavior. After a fair bit of use the memory structure in the card goes awry and the camera takes much more time to access and/or read/write the files. 

This is more prone with the SD cards than the CF cards. 

The flashing goes away once you do a low format the cards. It is advisable to use the option of a low level format with the SD card in the camera.


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## Menace (Feb 19, 2013)

J.R. said:


> Its normal behavior. After a fair bit of use the memory structure in the card goes awry and the camera takes much more time to access and/or read/write the files.
> 
> This is more prone with the SD cards than the CF cards.
> 
> The flashing goes away once you do a low format the cards. It is advisable to use the option of a low level format with the SD card in the camera.



+1


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## magnetized1221 (Apr 3, 2013)

my canon 5d3 power is off.when opening and closing the card slot it flickers..why is it my canon 7d dosent do that ..is this normal..


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## J.R. (Apr 3, 2013)

magnetized1221 said:


> my canon 5d3 power is off.when opening and closing the card slot it flickers..why is it my canon 7d dosent do that ..is this normal..



I don't remember if the 7D did that but both, the 5D3 and the 6D exhibit such behavior - Thus far, I haven't had any card trouble with either camera.


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## Fleetie (Apr 3, 2013)

I have seen this after deleting a lot of files from the CF card while the camera was connected to my computer.

Next time the camera is switched on, the light blinks for a while.

I always assumed that the camera was defragging the card.


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## timkbryant (Jun 24, 2013)

I've noticed that, but it's never resulted in any problems. It's probably how the camera shows it's acknowledging the card.



magnetized1221 said:


> my canon 5d3 power is off.when opening and closing the card slot it flickers..why is it my canon 7d dosent do that ..is this normal..


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## Mt Spokane Photography (Jun 24, 2013)

The shock from dropping the camera either damaged the printed circuit card by cracking it and causing a momentary issue that will appear now and then, or momentarily disconnected the continuity to one or more contacts on the memory card. Normally, the camera can handle a discontinuity of a few microseconds, but if it was longer, it might cause the issue.
If it happens again, I'd send it to Canon while its under warranty, if the end of the warranty is coming up, send it to them for evaluation. Loose connections or cracked traces on the motherboard can be very difficult to find, and will cause issues when you least expect them.


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## mb66energy (Jan 29, 2016)

Just to add an observation on a 5D classic (which had the same phenomenon):

Changing battery, CF card has not helped but:
removing and reinstalling the lens helped (EF 2.8 40 STM).
Perhaps some strange state due to incomplete contact between camera and lens ...


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