You scan and copy with ADF or flatbed?
Try both method couple of times and see if the problem persisted.
Have you open up the ADF unit to check if there is any stain/ dust? And did you also try lubricate the roller in ADF unit? I've work with one of this Samsung printer before and amazingly, lubricate the roller solve the problem.
If all done and the problem still there, I can tell is the scanning unit issue and its not worth to be repair at all.
Samsung All In One Printer, Scanner, Fax, Scanning Prob