Cannon T7i or 800D problems: takes exposure when turning on, won’t take picture w/ button.

[EliHayton]

Immediately starts taking exposures when powered in, continually. Shutter button auto focuses but doesn’t take a picture. Auto focus works, touch screen works to take exposure or picture. My dad is a astrophotographer and he was using his camera to take long 2 minute exposures at the sky all week all night long. Some pictures were green so then he updated to software and it worked. Then later last night yesterday 8/22/25 it wouldn’t take pictures and it had all those symptoms. We took it to a camera shop today and they don’t know what’s wrong with it. I’m trying to figure this out so if anyone has any information it will be very appreciative. Thank you!

[deebatman316]

Are you using any 3rd Party items on the camera. If so remove them and retest the camera.

[EliHayton]

The thing is, We dont have a battery for it so we use the dummy battery, or external battery. Would i have to get a battery then test if that works or is there another way?

[EliHayton]

We took the camera to a camera shop and they put in a real battery, but it was still behaving how it was earlier, however we did not do a reset while the new battery was in there.