It may be that the internal battery in the controller needs to be replaced. Remove the four screws from the front of the keypad, and check the voltage of the internal battery. The internal battery is a 3.6 Vdc battery. An indication that the internal battery may be failing is if the charge is down to 2.9 Vdc and if entered programs are not stored in memory. Replace the drained battery with a fresh one, but ensure that the sampler is plugged into a power source with the power on to keep the new internal battery from discharging.