The keyboard for the SAM4s SPS-520F and SPS-530F are the same part. This is an item that most end-users could change without much trouble. If you don't think you can please feel free to call us at 1-800-863-2274 to discuss other options.
These keyboards are very durable and withstand a lot of use. In our experience it is pretty rare that a keyboard fails. When we have encountered a failure it is almost always due to spillage or other items that don't belong in a cash register. The keyboards are spill resistant but not completely water proof. For whatever reason your keyboard has failed it is a pretty easy fix.
Please remember to unplug the register before repacing parts and most do it yourself repairs can void the factory warranty on the machine and the part.