07-18-2016 04:03 PM
Turn the power off. Take the memory card(s) out, take the battery out. Put the battery back in. Turn the camera on. Sometimes you can have issues when the boot flag is set on a memory card.
Are you using the HDMI port?
11-10-2017 11:06 PM - edited 11-10-2017 11:08 PM
This worked. I spent all day trying to figure this out via manual, canon site and other blogs. This last comment was the finishing word. All of the other suggestions were valid and I did use them to troubleshoot the problem A Thanks for your comment Buffdog or JonKline
03-01-2019 02:55 AM
03-14-2019 02:17 PM
I'm having the same issue with a 5D Mark III:
- at a shoot the LCD screen went dark.
- I popped battery and memory card but that didn't solve the problem.
- I've tried different batteries and memory cards. No luck.
- I've tried with no memory card inserted. No luck.
- When I power off the camera, the "sensor cleaning" message appears just fine.
- Occasionally the screen comes back when I fidget with the memory card access door.
- The memory card door snaps into place as expected. It's not loose at all.
Any ideas before I send it to CPS?
03-14-2019 02:36 PM - edited 03-14-2019 02:51 PM
That sounds very much like the symptoms I was experiencing except I didn't get anything from the screen at all. When the sensor cleaning message came up the shutter fired and the screen worked. Then it wouldn't next time I switched it on.
I thought I'd tried everything but you need to take out the battery and the card then replace the battery before putting the card back exactly as JonKline said above. This seems to reset the camera and so far all has been well for the last couple of weeks.
I checked the switch on the card door as I thought that might be the problem but if it were then there would have been no life at all in the camera. What was weird was the metering and AF worked but the screen and shutter release wouldn't.
Hope this does the trick for you.
03-14-2019 02:50 PM
Based on what I read here, I thought maybe the card door switch might be the problem, but nothing there is loose. I'm going to try replacing the clock battery and updating firmware (now that the screen seems to be back), and go from there.
It's an odd scenario that I haven't run into before!
03-14-2019 02:53 PM
Out posts must have crossed. It seems to be important to remove the battery and card then replace them in the right order. I had removed battery and card, put in new battery, different card but when I followed the sequence exactly as given by JonKline above all worked fine and has continued to do so.
Can't do any harm to replace the clock battery and you should always keep your firmware up do date so it would do no harm to check that and update if necessary. Good luck.
03-14-2019 02:58 PM
Thanks. I did follow that sequence before I posted here.
I'm just heading out to buy the replacement battery and will post back on what the result is.