How to repair abnormal behavior of Auto focus in my Nikon D50?

My Nikon D50's auto focus is behaving abnormally for the last few days. It gives the focus beep, even though the image is not actually focused. Moreover, even in broad daylight, it is taking a lot of time to focus, and I have to half-press the shutter multiple times to focus the image properly. I have tried out a lot of ways of mending the problem, starting from reseting the menu, to cleaning the lens and camera body contacts.

I'd contact Nikon and work out a way to have it repaired.

Is the problem with just a single lens? If so there's a fault in the lens

Is the prblem the same with several lenses? If so then there's a fault in the camera body.

Did you clean the CPU contacts? It's a common problem with the D50. Else it might be best to get in touch with Nikon. Hope you still got warranty.