I purchased a used NDX. It arrived today and I cannot get it to power up. I tried several outlets around the house, checked the two fuses next to the mains connection, changed the batteries in the remote and connected ethernet in and digital out (to a DAC).
I tried using the Naim app and didn’t have any luck.
Make sure you have the external power supply blanking plug attached at the rear. Refer to the manual if this is unclear to you (also available from the naim website if it wasn’t included),
Best of luck