It’s not really a dealbreaker, but you can expect a future board revision with a proper implementation of the USB-C protocol. But if you find yourself scratching your head and you don’t understand why your Raspberry Pi is not powering up, now you know why.
The Raspberry Pi Foundation has released the schematics of the board. And there’s a missing CC resistor that let sophisticated chargers negotiate current with the device.
Given that USB-C is a complicated connector, some cables are electronically marked, which means that they have an integrated chip to support a wide range of devices.
For instance, you can use a MacBook Pro charger with plenty of USB-C devices. The charger just figures out how much power it needs to deliver.
But the Raspberry Pi 4 doesn’t support electronically marked cables, such as Apple’s USB-C cables or Google’s Pixel 3 cables. The device is incorrectly identified as an audio adapter accessory.
Fortunately, it doesn’t damage the Raspberry Pi 4 and it doesn’t create any fire hazard. The device just doesn’t power up.
"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,” Raspberry Pi Foundation founder Eben Upton told TechRepublic.
A simple workaround is to buy a non e-marked cable or charger. The Raspberry Pi Foundation is selling an $8 USB-C charger for instance. In my testing, it has been working fine for the past couple of weeks.