I'm trying to repair a Rebel T6 with a strange problem. All settings are stock, AF One Shot, center point selection. I've tested with 3 lenses including the 18-55 kit lens. After turning the camera on, it focuses quickly and accurately with the viewfinder, near and far, in all zoom ranges.
However, after taking a photo, it refuses to focus on anything - going back and forth in the focus range and never finding focus. It stays this way until I wait a while (5 minutes or so). Changing lenses, turning the camera off and on again, removing and replacing the battery, none seem to affect whether the camera will autofocus again.
Steps I've taken:
- ensured the environment is well lit, focusing on high contrast subjects
- cleaning lens and mount contacts
- cleaning the mirror
- cleaning the focus screen (last resort)
Live mode focus does work, but seems to take a long time (1-2 seconds) in making small adjustments to find focus. I haven't used a T6 before, but it seems like it should focus faster than this.
Any help would be appreciated. I'm comfortable with taking the camera apart to figure it out, this was a $50 eBay buy.