I have an Identical issue and this is what I tried:[br]
- Replacing the power board attachment with ribbon cable.[br]
- Replacing the battery.[br]
- Resetting controller by pressing the button on the back.
I can use it only when it’s connected to the charger or powerbank (Bluetooth works) but once I unplug it controller forgets about being synced and pairing has to be done once again… Any ideas which part on the motherboard should be checked?