I have a samsung fridge/freezer model no.Frost free RL38SCSW.there is a build up of ice on the bottom shelf of the freezer compartment.

SOURCE: fridge and freezer not staying cold

There should be a circuit board on the inside of your refrigerator behind the plastic panel it's a switch that tells the refrigerator to get cold. I had mine replaced it cost about 150.00. Hope this helps.

SOURCE: water seepage at the bottom or floor of freezer

You will want to check the rear of the fridge. There is an access panel there you can remove. Once removed, you can then check the drain hose and evaporator tray. There should be some water in the evap tray, if not, then the drain hose is plugged and causing water to run on floor.