I have a Canon 5D mark IV. It was working fine till a few days back. Suddenly it has started taking around 5-8 seconds to turn on. I can't figure out why this is happening. Does anyone have a clue about it?

Edit: One more observation is that it is getting hot even when turned off in my office.

Note: For people blaming battery, I checked with a different set of batteries from my other 5DM4 camera, same issue persists.

  • \$\begingroup\$ Have you checked the battery? \$\endgroup\$
    – inkista
    Oct 14, 2019 at 17:32
  • \$\begingroup\$ What kind of batteries are you using? Recent Canon EOM? Older Canon OEM? Recent third party? Older third party? \$\endgroup\$
    – Michael C
    Oct 14, 2019 at 23:35
  • \$\begingroup\$ Yes, checked with multiple batteries. It still takes time to turn on. \$\endgroup\$ Oct 15, 2019 at 9:40
  • \$\begingroup\$ Its original canon battery purchased recently from Canon store. \$\endgroup\$ Oct 15, 2019 at 9:40
  • 2
    \$\begingroup\$ Can you provide step-by-step what is happening once you flick the switch? do any lights come on? does the screen show anything? what shows first? pay especially attention to the red light bottom right that indicates whether it is accessing media card or not. I've got the same camera myself so will test a couple of things if I get the chance to see if I can replicate. \$\endgroup\$
    – AutoBaker
    Oct 18, 2019 at 9:36

5 Answers 5


Want to build on @Michael-C answer.

Definitely try to think if you've changed anything since it's started behaving weirdly. But I suspect you may start having to dig deeper. However it's worth a try:

  • Have you changed any settings?
  • Have you used a different card / battery / lens to usual?
  • Has there been any software changes? Firmware upgrades etc? Software such as Magic Lantern can be used to overwrite the Canon software and provide further features. If so, it may need to be taken to a Canon partner to get it fixed.

Top end DSLR's are almost infinitely configurable, so it's worth reducing it to basics before you start troubleshooting. Accessories can affect it in different way.

Remove every consumer accessory you possibly can:

  • Remote flashes, battery grips, self timers, monitors etc.
  • Remove the lens and replace with a body cap.
  • Remove all media cards.
  • Remove the battery and replace with a freshly charged Canon battery.

If you have already reset the settings, and none of the above makes any difference, do a thorough physical check of the camera:

  • Are there any cracks or chips on the casing? Physical damage could have caused internal issues.
  • Check inside the battery and memory card compartments - are there any bent pins? Corrosion? Water or other foreign bodies?
  • Check the sensor and the area around it with a torch - is there any oil or visible residue (if the camera gets too hot for instance, the oil in cameras which should be highly viscous can become runny and damage components).
  • Check the other ports on the body for foreign body ingress, bent or damaged pins, etc.

If there's still nothing obvious, you could try a firmware upgrade:

And lastly, take it to a Canon repair centre. You will have to send off your camera for a minimum of 1-2 weeks and it will likely cost you above £100.

DISCLAIMER: don't attempt any repairs yourself, and take care when examining or exposing internal parts of your camera. Refer to the manual for correct usage.

Hope that helps.

  • 1
    \$\begingroup\$ Your answer helped me a lot in diagnosis. It was indeed a bent pin. I am accepting your answer but have written my own answer for a quick fix if someone else faces this exact issue. \$\endgroup\$ Oct 20, 2019 at 16:13
  • \$\begingroup\$ None of the repairs I've sent off to Canon have ever taken more than eight days from the time I shipped them until I got them back, and that's when the shipping in both directions included a weekend. I am in the U.S. and a member of CPS. YMMV. \$\endgroup\$
    – Michael C
    Oct 20, 2019 at 23:36
  • \$\begingroup\$ Yep, and I'm in the UK. If it's quicker then it's a bonus but I always make sure I've got 2 weeks camera-free use planned out, as that seems about average. \$\endgroup\$
    – AutoBaker
    Oct 24, 2019 at 8:00
  • 1
    \$\begingroup\$ @AtmeshMishra - Glad I could help. Incidentally I decided to do a firmware upgrade at the same time, so it's helped me keep up to date. \$\endgroup\$
    – AutoBaker
    Oct 24, 2019 at 8:03

There are a few different possibilities. Before getting into particulars, you should probably start by asking yourself:

"What else was changed when the camera began starting up slower?"

That will almost always point you in the right direction to what is causing the different behavior by the camera.

  • Did you use a different battery than before? Particularly a third party battery?
  • Even older genuine Canon batteries in newer model camera bodies can sometimes not work as smoothly as expected.¹
  • A different memory card?
  • Have files not created by the camera been added to the memory card?
  • Has the memory card been formatted in a device other than the camera?
  • Has the memory card been most recently used in another camera?

I've experienced a similar delay when using older third party batteries with newer camera models. Sometimes, after the short delay, the camera will recognize the battery as "genuine", sometimes not.

This is due to the way third party batteries are "reverse engineered" to work with models that are in use when the batteries are designed. Canon will occasionally tweak their battery communication protocol that makes the third party batteries less than fully functional with the new models. It usually only takes a few weeks for the third party battery makers to update the firmware in the batteries they are making to comply with the changes.

Since the camera accesses the memory card during startup, anything to do with the memory card that throws the camera a "curveball" can delay successful completion of the startup routine.

¹ For example, when Canon released the 5D Mark III in 2012 and the subsequent 7D mark II in 2014, they started calling on code in their battery communication protocol that had previously been "hidden" (i.e. present in the code but not used in actual camera/battery communications so that third party "reverse engineering would not detect it). This made almost every existing third party LP-E6 clone at least partially "obsolete" when used with one of the newer cameras. Unfortunately for Canon, they also accidentally rendered some older genuine Canon LP-E6 batteries equally non-fully functional. The updated chargers supplied with the new cameras would refuse to charge them as "not authentic".


This has happened for me - and I believe I found out it was because the camera indexes the entire memory card while booting up - and the more packed the memory card was, the longer it took at boot.

I would begin troubleshooting your device by archiving the data from the card, reformatting the card and restarting with an empty, newly-reformatted card.

  • \$\begingroup\$ The card is empty. I will try reformatting it once though! \$\endgroup\$ Oct 15, 2019 at 9:41
  • \$\begingroup\$ @joshjurg - is yours the same camera? I've got a 5D IV and have started it up with a full 120 GB SD card (inherently slower then the CF cards it also can take) and there's been no problem - started up as quick as ever. \$\endgroup\$
    – AutoBaker
    Oct 18, 2019 at 9:54
  • \$\begingroup\$ No, it's not. My guess was that it could be a cross-platform issue, though. \$\endgroup\$
    – Joshjurg
    Oct 18, 2019 at 12:54

Finally figured it out what was wrong with it and thankfully it was nothing major. I noticed that it was taking time to come to normal state(info on screen) after 7-8 seconds even if I just opened the SD card lid and closed it. This made me certain that something was wrong with the card or the pins.

I put a flashlight and saw 2 pins in the CF slot stuck together. I separated them using my tool and now the camera is working fine.

Word of caution for everyone: Check the CF card for dust or stray particles before using it.

  • 3
    \$\begingroup\$ Any time you open the memory card door, the camera shuts off and will go through the same startup routine when the door is closed as it would go through if the main power switch were cycled off and back on. In your case it was a memory card slot issue, but even if the issue had been something else, it would had still manifested itself by opening and closing the memory card door. Ditto with the battery compartment door. \$\endgroup\$
    – Michael C
    Oct 20, 2019 at 23:39

Could be consistency checks on the media in case the camera does no longer consider itself sure about its organisation, like its index files (typically created when media are formatted in-camera) having diverged from media content.

Does this also happen with a fresh media formatted in-camera?


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