Replacement Power Supply

Thread Starter


Joined Jun 30, 2020

I have a small home-use electronic device and the power supply cord has been damaged and no longer properly fits into the device. (the device works; the cord is just damaged)

I want to avoid contacting the company and dealing with their customer support; I'm hoping someone here can give me some general guidance on finding an appropriate replacement on Amazon or somewhere similar.

I've attached images of the power supply cord and the device's power input. The wall outlet supplies 120V (US/Canada standard)

Thank you!!!


Audioguru again

Joined Oct 21, 2019
It is easy to find a power supply that produces 5VDC at 3.1A or more with a plug having positive inside, but the problem is the size of the plug and the size of the hole in it must match the product it plugs into.

Thread Starter


Joined Jun 30, 2020
Thanks for the response. Yes, I recognize finding the right size is also the issue. Is there a standard increments that they go in or system of measurement? How can I measure the size of the hole/plug to find the correct match?

Additionally... Yes, I am looking to find a complete plug/wall adapter. I am not an electrician, so I need a fairly straightforward solution.

Thank you!


Joined Dec 19, 2007
You can purchase replacement plugs. Do you have the skill to attach and solder the wire to a new plug? Can you measure the outside diameter of the plug barrel? It will be metric? The inside diameter will be a little harder. Maybe you can measure the outside diameter of the pin on the device. Here is a table of the dimensions of standard "coaxial power connectors":
Connector selections
And a couple of videos:
My $.02. It's generally a PITA to figure out what you have.

I had one very difficult animal that was 3.5/1.2 for a DSL modem. That is a really rare plug. I wanted to power the DSL modem from a POE adapter.

Anyway, when I buy stuff, I tend to label everything with a p-touch labeler.

It might say
5 VDC , 2A
5.5/2.1 C+
Asus ####

With two wire labels.

This helps a LOT. I mark the device as well.

I have calipers, so that helps. I also have a full set of SAE drill bits and that really helps.
Then you have the list of possibilities:

If you don't have that, take a picture with something that you do know. Coins have known dimensions. A ruler works too. So you can use the picture of the object with a ruler oriented properly to make a guess at the dimensions. Then check with the list of adapter sizes.

The drill and caliper method is better. Using known plugs/jacks is better yet.

It's real IMPORTANT Not to use the 5.5/2.5 on the 5.5/2.1 jack.

I made up an adapter with 5.5/2.1 and 5.5/2.5 input connectors with an Adapt-a-plug pigtail. I used a Hammond case that's translucent to the display.

This is a bit more modern than what I used. You can blank the display on this one.

I think i used a case similar to:

Anyway the device is pretty nice because you can replace a broken adapter very quickly. 5V is a common adapter so you need a 12V adapter. With a 24 VDC adapter, I could even run my ASUS router at 19V. I used it to make a 6V adapter and I'm still using it.

So, the voltage has to match.
The current has to be equal or greater than the adapter usually.
The current that has to be greater or equal to the device power requirements.
It's not really a good idea to use a 5A adapter for a 0.1A device, but it will work.
It has to have the right plug and polarity.