A bug has recently been identified with the USB Type-C implementation on the new Raspberry Pi 4 single board computer and was officially confirmed by co-creator Eben Upton.
“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,” says Upton.
“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.”
Apparently, the Raspberry Pi 4 refuses to take power from certain USB Type-C cables. Most notably ones that users have re-purposed from Macbooks and other new Type-C powered laptops.
Without getting overly technical, what is happening here is that certain cables identify the Raspberry Pi 4 incorrectly as an audio adapter accessory and then refuse to provide sufficient power.
The solution for now – either use the official Raspberry Type-C power adapter or a non e-marked Type-C cable. What is that, you may ask? Well, then read the next paragraph for a more nerdy explanation, or simply skip it if that’s not your cup of tea.
Electronically marking Type-C cables refers to the process of implementing certain maker chips on one or both ends of the cable. The USB specification allows for these to be connected in two main ways and come in two flavors – passive and active, mostly depending on whether they need to augment the actual data transfer through the cable or not. Furthermore, e-marked cables are required if you need a full-featured cable, like one that needs USB 3.1 Gen1 or Gen2 (which are no longer called that), or uses USB Alt-Mode or provides more than 3 amps of current. The Type-C cables that ship with most laptops likely tick at least one of these boxes, which is what apparently causes the Raspberry Pi 4 incompatibility.