Re: uploaded photos and videos to my computer now my videos have sound but no picture
Welcome to Android Central! Which phone? How did you move the files? Were you using Windows Explorer? Did you use the Move command, or the Copy command? Always use Copy, because that leaves the original file alone, which is important in case the file gets corrupted during the transfer. Move deletes the original once the transfer is complete.
Were the videos originally on the phone's Internal Storage or the microSD card? Files on a microSD card have more chance of getting corrupted than on Internal Storage.