What to check
The PinNet controller PCB has a Red LED located in the top right corner, and a power source from
either the power module (18v DC) or an external power unit 12v DC.
Corrective action
Replace the PinNet controller or power supply.
The externally mounted header chip contains all the data for the system. It can be transferred to a new PinNet without the need for re-programming.
Links
https://www.entryphone.co.uk/pdf/PinNetManualV5.pdf