negative voltage damaged something in my arduino mega pls help

hi..im using arduino to acquire a signal from sensor through its analog port A0...i shifted the signal to the positive part but sometimes the signal have negative part ... when i running my project something damaged and white smoke appears in the part of arduino mega 2560 as shown in figure below

how to solve this problem pls?

Replace the damaged part and make necessary precautions so that you don't feed negative voltage to Arduino again.

the cap CS47 25v ...may be damaged but there is no bulge appears...how to checked ? it is printed on the board

If one cap smoked, the other is damaged as well. You will need to replace them both.

There may be other damaged components as well.

Things that are damaged do not always fail immediately.

the arduino is working ...i checked it by applying voltage through USB port .... but the analog port read wrong values !!

dany151: the arduino is working ...i checked it by applying voltage through USB port .... but the analog port read wrong values !!

Maybe that input is whacked. Have you tried any of the others?