Main camera does not work

Hi,

I have some problems with the main camera of my S20 Fe 5G.

A couple of months ago my smartphone hit the ground and the display broke. Apparently I had no warranty because I bought the US model but live in Europe...

Anyway, I bought a new display and exchanged it myself. Everything worked fine. Some days ago I dropped the smartphone again, and now the main camera does not work anymore.

I have used the diagnosis tool to check on problems, and no connection can be found to the main camera. Opening the app only says Camera Error.

I have downloaded another app (Open Camera) and am able to switch between the different camera types now.

ID 2 and 3 (front and wide front camera) as well as ID 4 (ultrawide main camera) all work fine.

ID 0 (main camera) has no connection.

I have bought another main camera to replace it, but it did not work.

I have come to the conclusion that:

1. The "new" camera is also broken, as I bought it used, OR

2. There is a problem with the motherboard, probably due to the first fall.

When replacing the display, I was worried about other broken parts, but they looked generally fine. Except the light sensor has a crack.

Is there a way I can verify which part is broken before buying new parts, as I don't have much money to waste.

I appreciate all the help you can give me and will make sure to take a class on "Don't Let Your Phone Fall."

Thanks

Lenard