AC200MAX Display Responsive but AC/DC Controls Non-Functional

Verify the symptom by attempting to toggle AC or DC outputs directly on the unit's touchscreen interface. Confirm the failure if the screen registers touch input (visual feedback occurs) but the output status remains unchanged. Verify that the Bluetooth app is capable of successfully toggling the same AC or DC outputs, which confirms that the main power board and inverter logic are functioning correctly despite the touchscreen command failure.