How to: Select a replacement power adapter for your electronics (e.g. for an Asus router)

Every once in a while I find a nice cheap ASUS router without a power adapter, hunting for the specific adapter that came with the router can be a pain and often times power supply prices are unreasonable. But it’s not necessary to buy the exact same one so you can find a much cheaper power supply. Here I will describe how to find a matching power supply for your router

Take a look below for a list of power supplies for ASUS routers, and if there is one missing send a comment and I’ll update it!

Barrel Adapter

  • The barrel adapter has to fit the power jack. This needs to match in outer diameter and inner diameter. Look for your original power supply and try to determine what these dimensions are. Once you know you can filter your search by only these sizes.

Voltage and Amps

  • Volts: You want to match the voltage exactly so for a 19V router you need to find a 19 volt power adapter.
  • Amps: This one is a bit more flexible, your device will only use as many amps as it needs, find a power supply with matching amperage to your original OR LARGER, a smaller power supply will overheat since your device will try to pull more than the power adapter can suppy
  • Remember Watts = Volts(V) X Amps(I)
    • So a 19V power supply providing 1.75Amps can output MAX 33Watts


  • This is more or less standard but every once in a while you’ll get a device with reversed polarity. For the most part you will find ground(-) on the outside and positive(+) on the inside. Make sure to match this exactly.
What Is Polarity in Electricity

Below is a list of ASUS router power supplies and their specs

If you find a power supply not listed please send me a comment and I’ll update it!

Searching Tips

Searching for a replacement on ebay can be done by putting all the compatible models in a comma separated list in parenthesis. So for example, all the power adapters below that work with my router can be search for on ebay by searching using the string below

  • (ADP-33AW, ADP-45BW, ADP-65DW, ADP-65DW, AD890326)