Check that the battery is well charged> Press the battery button> Check that at least one LED is turning on> If one of the LEDs is flashing, recharge the battery by connecting it to its charger and a socket 2. Check that the battery is clean, properly attached and locked in place > Check that the battery's connectors and holder are clean and in good condition.> The battery should be pushed all the way into its holderWhen you push it in, it will click to indicate that it is correctly in place.Lock the battery and remove the key. 3. Check that the cable linking the console to the controller is connected (the controller is the central processing unit under the pannier rack, just behind the battery) > Open the rip-tab cable cover that you'll find between the pannier rack and the saddle. > Check the accessory cable connection (the one with the metal rings). > To check if the connectors are clean, in good condition, and correctly inserted, unscrew both rings on either side of the black washer. > Check that each connector is clean and in good condition > Reconnect everything properly. To do this, position each male and female connector opposite each other and align the indicator arrows before pushing them back in.Make sure you don't forget the washer between the two rings. > Tighten the rings as far as they'll go in order to secure the connections.  4. Check that the screen is connected > At the front of the bike, slide the neoprene cover off the screen to reveal the pair of connectors for the screen (black). > Do the same as before to check the console's connections.  5. Press the ON/OFF button to switch the screen on If the problem persists, submit a support request or visit a Decathlon workshop.