My daughter has Fujifilm Instax Mini 9, and all 4 LEDs are blinking non-stop. Changed batteries to new. No success. Checked battery positions. Correct to the raised lettering orientation. Took camera apart and found the aperture button circuitry. Pressed the button and saw the voltage changed therefore that is working. Beyond that, I am not familiar with the main circuit board to do anymore diagnostics. Does anyone has any other suggestion on what else to check? Thank you.