System not powering up but Bluetooth cycling on and off continuously

[Abarth695]

Don’t know what has changed or why
Controller not powering up and Bluetooth cycling on and off all the time
I have power as the green light of the modules are on but the controller doesn’t power on and as I said Bluetooth keeps on cycling on off on off. LED is powered on
Can anyone help
I’ve had the unit for years and set up is pretty basic but I’m stuck as to why this is happening
Whole unit apart from the controller switch was sent away and confirmed all ok
Is the control switch stuffed but then why is Bluetooth going on and off
Appreciate any advice