EOS Rebel T100 won't focus, won't take photo, sometimes freezes

[Ericaharvey]

I am having issues taking photos with my Canon EOS Rebel T100 / 4000D camera only bought about 6 months ago. It was working fine until after I did not use it for about a month or two. It is not focusing, and does not take photos unless on MF mode. Screen will also go black or sometimes freezes while trying to take a photo. Only resets when the battery is taken out and put back in again but still having the same problem not taking photos. I sent the camera and lens into Canon to be looked at as a faulty lens code was coming up, they sent it back shortly after stating no issues were found. However it is still not taking photos hassle free.

[ebiggs1]

"However it is still not taking photos hassle free."

This is almost always user error, not saying it is this time but let's find out.

First do another full reset  (back to basics) if you don't know how check your manual. Afterwards set it to P mode. One shot and make sure the lens is on AF not MF. ISO 200. Daylight WB and large jpg. Now on a nice day go outside and take a dozen or two random shots. If it works, it works. Make sure you do not change any other settings this is very important.

I'm taking for granted you are using a known good fully charged Canon brand battery and a top quality SD (no micro-SD) card preferably formatted by the camera.

Never use a micro-SD with an adapter and never a SD bought from Amazon or eBay. Actually if you did buy it from Amazon itself it is probably OK but you need to make sure the retailer you bought it from is Amazon and not Amazon Marketplace. Amazon Marketplace is not a 100% known good retailer.

[Ericaharvey]

I have tried these things you have suggested including a full reset. It still will not take photos. When attempting to take a photo, the screen will go black or it will freeze and not do anything. The battery is a Canon battery but I’m not sure if the SD card could possibly be causing these problems? It worked perfectly fine before but just started having these problems after not being used for a few months.

[ebiggs1]

If you did the steps exactly as I recommend and it still doesn't work I am afraid it is faulty and needs service. However, service may not be possible due to cost VS value or even if it is still a serviceable camera.

Now you mentioned the SD, it is a good idea to buy a top quality brand new SD and try the exact same steps once again.  You are certain you are not using a micro-SD. You must use a full size SD and the precise one recommended in your Canon manual. You can d/l a manul if you need one.