When batteries leak, you will find traces of battery chemistry on the electronics (circuit board). You must cleanly remove these traces in order to get your hörbert back in shape. Cleaning after leaking batteries: Important safety instructions Take care of your safety and that of your surroundings in the following activities! Only work with safety glasses! Only work with protective gloves! Don't touch anything else with your gloves on! Work with an open window and sufficient fresh air supply! Do not work near flames or ignition sources! Keep chemicals and tools away from children! This manual does not apply to other devices! Leave the repair to us, if you don't think you can take a step! Risk of injury: splashes of alcohol or battery chemistry in the eyes may cause serious eye injury. In the event of an accident, consult a doctor immediately. Fires may occur when working with high-proof alcohol. Have extinguishing agent ready. Alcohol can dry out your skin, so wear gloves! And again: Keep children away from chemicals and tools! And so it goes: Pull the memory card out of the memory card holder. Check the contacts on the memory card. It may need to be replaced when it has received battery chemistry. You can try cleaning them with alcohol. Remove the electronics by loosening the 4 nuts on the board. Lift up the board and disconnect all 3 cables. Find all traces of battery chemistry on the top AND bottom of the board. You'll need to clean it very carefully to stop the corrosion. Use plenty of isopropyl alcohol 70% (e.g. from the pharmacy): Drip the alcohol abundantly on all places where you find traces of battery chemistry. Soak everything. If the alcohol evaporates, drip more of it onto the board, even into the memory card holder. Use your toothbrush to scrupulously remove all traces of battery chemistry. Cotton swabs can also help. Important: NEVER scratch! Because if you scratch a trace or destroy a small component, it is very likely that the board is finally broken. When everything is clean, let the alcohol evaporate for an hour. Never use the electronics in wet condition. Now you can plug all cables back in where they were, insert the board again and screw it tight. Now insert the batteries and the memory card again and switch on audibly. Don't forget to breathe.