Excuse for the late answers! Psu is 12V 2A en we checked it. Psu is allright. The Minix was in the original box and cables etc were sealed. It is really the Max version as shown on the button. Also tried different wall sockets. My own thought maybe software is corrupted. Don't know if it is possible to load new software with pc.
You could try and reflash the box using the burning tool method on a Windows PC. I know you said that it only shows a standby light when you power up the box. But it might be worth a try.
Or, it might be worth buying a new psu. I am no technical expert, but it is possible that the male connector, which has a negative and positive connection is faulty, and thus only provides a standby light on the box.
If all that doesn't work, I would contact Alex at Minix and they may have a solution.
Or indeed they may allow you to return it to them for repair. Sure,it will cost the postage, but it is well worth it.
Good luck.