There could be a number of reasons why your appliance isn't working. Assuming that the device itself is still operational, possible causes include:
1. Insufficient or no contact between the battery and the terminal.
- The sizes of rechargeable batteries and alkaline batteries may differ. As a result, appliances designed to match the characteristics of alkaline batteries may have some difficulty fitting the batteries in. If this is the case, an alkaline battery should be used.
- There is dirt or leakage residue on the terminal.
2. Something is wrong with the batteries:
- One of them is completely discharged.
- One of the batteries has degraded or is completely dead, rendering it unfit for use.