@bw65587 

You can't buy M9 Plus power adapter, not from official sources, but you can have a replacement. My North American Deco M9 Plus is 12V 2A, check what is yours - it is on the label on the bottom of the device.

Then, take a look at this forum topic to find what is the barrel size of Deco M9 Plus power cable: Deco M9 Plus power adapter barrel plug size

They say it is "5.3(+/- 0.2)mm, and the internal diameter is 2.1(+/-0.1)mm."

Then, check on Amazon "12V 2A power supply" and check what barrel size it comes with. In my North American region the following, one of many, appears in the search: "Tonton 12V 2A/2000MA Power Supply Adapter, AC 100-240V to DC 12 Volt 2 Amp, for 12V CCTV Security Camera, LED Strip Lights, Router, Monitor, Razor Power Core E90, 2.1mm X 5.5mm Plug"

It goes for $14 CAD, which is not expensive.

Make sure it is "Shipped from Amazon" and not by third party, and also that it is "Eligible for Return, Refund or Replacement within 30 days of receipt." This product is, in my region.

For me, this would be the end of search: if I needed to replace my M9 Plus power adapter I'll go with that product.