T2i will not focus through eyepiece, but focus with Live View

[T2I753]

I am new to Canon, so perhaps I am missing something obvious.  I recently got a used T2i with the 18-55 kit lens.  The camera is pretty beaten up.  I have not been able to focus the camera through eyepiece.   When I half-press the shutter, the lens will turn and try to find focus, but it never achieves and no focus confirmation light.  However, when I switch to LiveView, I am able to focus and take pictures.    Since i got it used, I had reset all the previous settings and customization, but did not help with focus.   Any suggestions I can try ?  Thanks

[kvbarkley]

Look in the mirror box and see if anything might be blocking the AF chip.

[T2I753]

Thanks kvbarkley.  I looked online but cannot find where is the AF chip located.  Is it around/behind the focus screen?  Do I need to remove the focus screen first?  

[kvbarkley]

It is at the bottom of the camera, you can only see it if the mirror is swung up - the cleaning function

https://www.canon-europe.com/pro/infobank/autofocus/

[T2I753]

Thanks for the explanation.  I used the "clean" function to flip up the mirror.  Not sure everything was where they should be, but did not see any obstruction.  Used the blower to clean all inside, cleaned the lens contacts etc.   Still no luck.  

[kvbarkley]

You will probably need to send it in for repair.