How to plug in your USB Type A connector correctly the first time

Raymond Chen

Nearly every USB plug has a USB logo printed on one side. Use this one weird trick: Plug it in with that side facing up.¹

Make sure it’s the USB logo that’s facing up. The manufacturer logo, if present, faces down.

When I find a plug that lacks a logo. I put a small sticker on the “top” side.

Most power adapters in the United States are unpolarized two-prong Type A, which means that they can be plugged into the wall in either orientation. I write the amperage on a small sticker and stick it to the “top” side of the adapter.

There are some manufacturers who install their USB receptacles sideways or (heaven forfend) upside-down. I use a small sticker to identify the “logical top” side of those receptacles.

¹ “Rule of thumb: Thumb on the logo.”

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Raymond Chen

Raymond has been involved in the evolution of Windows for more than 30 years. In 2003, he began a Web site known as The Old New Thing which has grown in popularity far beyond his wildest imagination, a development which still gives him the heebie-jeebies. The Web site spawned a book, coincidentally also titled The Old New Thing (Addison Wesley 2007). He occasionally appears on the Windows Dev Docs Twitter account to tell stories which convey no useful information.

20 comments

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Péter Ádám October 13, 2020

My XtremeMac A to C cable is bidirectional on the A side, too.
dexi lin October 12, 2020
```
while (true)
{
    FacingUp = !FacingUp;
}
```
aidtopia October 8, 2020

I suspect the convenience of Type C’s reversibility comes at the cost of lifespan. The contacts are much smaller than the ones on a Type A connector (for a variety of reasons, including reversibility). As cables are disconnected and reconnected, the contacts will wear, and, presumably, smaller contacts will wear out faster. And the higher current ratings of Type C means the smaller contacts are already closer to the minimum size required. In fact, to get the rated 5A, the current is split across four pairs of conductors.
- Jernej Simončič October 13, 2020
  
  I’ve had a few permanently connected USB-C cables stop working for no visible reason (the cable simply wouldn’t be held in the socket any more). These were USB-C to DisplayPort used on NUCs.
- David Walker October 8, 2020
  
  If it’s a connector you are plugging and unplugging a lot, you’ll probably lose the cable (or other device) before the contacts wear out….
ben@decadent.org.uk October 7, 2020

I’m not sure the logos are all that consistent. I orient USB A plugs using the join in the metal shielding, which seems to always be on the underside.