Raspberry Pi 4 Model B Units Facing USB Type C Power Problem Have Some Simple Workarounds Despite Glaring Design Flaws

The Raspberry Pi Foundation recently launched the fourth iteration of its immensely popular single-board computer, the Raspberry Pi 4 Model B. Soon after, several units purchased by eager buyers failed to power up through the USB Type C port. The foundation swiftly conducted its own internal investigation and has confirmed its brand-new Raspberry Pi 4 Model B has a problem with some USB Type C cables failing to charge the single-board computer. Buyers have been quite vocal about the weird issue that appears to be a hardware failure. While the issue lies in the way the hardware is designed, there are a few simple and effective workarounds.

The Raspberry Pi Foundation has openly acknowledged that the recently released Raspberry Pi 4 won’t work when powered using certain USB Type C cables. The affordable single-board computer is by far the most popular choice for developers who work on the Internet of Things (IoT) projects. Besides several new and improved hardware elements, including better processor, dual micro HDMI out ports and up to 4 GB RAM, the Raspberry Pi 4 Model B is the first Pi board to use a USB-C power socket. Incidentally, the new iteration does not have a dedicated power supply port and has to completely depend on USB Type C port. In other words, the fourth edition of Raspberry Pi is the first one to include a USB-C port capable of supplying power to it.

Several users and early adopters of Raspberry Pi 4 Model B quickly realized that certain types of USB Type C cables simply fail to power up the single board computer. Incidentally, many users have strongly claimed that all USB Type C cables that have the ability to deliver power as well as transmit data should have worked with the new Raspberry Pi 4 Model B if the Raspberry Pi Foundation had simply followed the USB-C specification correctly and thoroughly. In other words, the foundation appears to have missed a few simple but critical design cues and protocols that would have ensured the USB Type C port on the new model accepted power delivery from all compatible cables.

Why Can’t The New Raspberry Pi 4 Model B Accept Power From Certain USB Type C Cables?

The weird issue was first reported by Liliputing, a platform that regularly tests single board computers. Following the inflow of several reports of certain USB Type C cables not working with the Raspberry Pi 4 Model B, Raspberry Pi co-founder Eben Upton acknowledged the issue and attempted to offer an explanation about the phenomenon.

According to Upton, the new Raspberry Pi 4 doesn’t receive power when used with electronically marked or e-marked USB-C cables. These new generation cables are typically used by Apple MacBooks and other laptops. Needless to add, these cables have been specifically designed with safety as a prime concern. They have inbuilt protection which prevents the flow of electricity if there’s a mismatch between the delivery and the acceptance of power. In other words, the cables are smart enough to first establish a common standard of power delivery and only then allow power to flow.

Speaking about the issue, Upton said, “A smart charger with an e-marked cable will incorrectly identify the Raspberry Pi 4 as an audio adapter accessory, and refuse to provide power. I expect this will be fixed in a future board revision, but for now, users will need to apply one of the suggested workarounds. It’s surprising this didn’t show up in our (quite extensive) field testing program.”

Benson Leung, a Google Chrome OS engineer, has long been fighting for a stricter and more uniform testing and approval standard for USB Type C cables and chargers. USB Type C is relatively a new standard or port for data and power delivery. It is faster, efficient, and capable of delivering a large amount of power as compared to its predecessor, the micro USB port. However, the micro USB port has been inactive, commercial use for a long time, and hence there are well-established standards for the same.

Leung claims Raspberry Pi engineers made a “common USB-C hardware design mistake”. Owing to the design flaw within the new single-board computer simply renders quite a few USB Type C cables incapable of delivering power. As mentioned before, if the Raspberry Pi 4 is incorrectly identified as an audio adapter accessory, even compliant USB-C chargers will deliver zero volts instead of the 5 volts needed by the single board computer.

Leung has long back criticized Raspberry Pi makers for seemingly failing to have done sufficient testing. He explains that from a technical perspective, the USB-C specification defines two pins called CC1 and CC2 for connecting to the power sink in a specific way. Raspberry Pi designers apparently deviated from it in two critical ways.

“The first is that they designed this circuit themselves, perhaps trying to do something clever with current level detection, but failing to do it right. Instead of trying to come up with some clever circuit, hardware designers should simply copy the figure from the USB-C Spec exactly. The second mistake is that they didn’t actually test their Pi 4 design with advanced cables. I get it, the USB-C cable situation is confusing and messy, and I’ve covered it in detail that there are numerous different cables.”

How To Power The New Raspberry Pi 4 Model B With Any USB Type C Cable?

Although the new models of Raspberry Pi 4 Model B typically refuse to be powered up by some modern USB Type C cables, there are a few simple workarounds. Raspberry Pi 4 owners will need to use non-e-marked USB-C cables. These cables are shipped with most smartphone chargers. The other simple method to power the new Raspberry Pi 4 through USB Type C port is by using older chargers with A-C cables or micro USB to Type C adaptors. Essentially, any old power delivery method can work as long as it can deliver 5.1 volts and 3 amperes.

Incidentally, there are very few old AC chargers with the ability to deliver 5.1 volts and 3 amperes. However, several modern-day chargers are able to deliver far more power owing to newer Fast Charging standards. In other words, combining a new smartphone charger with an old USB Type C cable is a workable option. The most obvious, reliable and recommended option is to buy the official Raspberry Pi 4 power supply. However, at $8 or £8 it is certainly not a cheap option.

Alap Naik Desai

A B.Tech Plastics (UDCT) and a Windows enthusiast. Optimizing the OS, exploring software, searching and deploying solutions to strange and weird issues is Alap's main interest.