I recently changed my lumia lcd and digitizer because the orginal screen was cracked. Everything works fine so far but the camera keeps coming on automatically. What might be the problem?
If I remember right, the Lumia 920 is a model with a dedicated camera button - if this is held down, the camera will start. It is likely the case that whilst changing the screen "something" is either causing the button to be depressed too easily (lost spring?) or is shorting the contacts.
I'd suggest checking there is the correct physical resistance on the shutter button (it should have a focus midpoint, as well as a take position, which you should normally be able to feel when using the phone.
If not, and only as you were happy to change the screen yourself, you might need to dismantle the phone again, and check all the springs are present and correct, and nothing is keeping the button pressed when it shouldn't be.