Eben Upton, founder of the Raspberry Pi Foundation, admits that the recently published Power over Ethernet expansion for the RaspBerry Pi Model 3+ in some cases provides too little power to USB ports. Buyers can exchange the sign.
Upton says to The Register that less than 200mA is delivered, which can cause problems with various peripherals such as external hard drives. In a new production series, the problems are solved, but the already produced PoE expansions that present problems are only given a notice informing buyers.
The problem is caused by the way the low-frequency voltage regulator on the PoE extension supply USB ports. The current regulator on some RPi 3 + boards can not handle this properly and thinks that a short circuit occurs, limiting the current.
Affected buyers can choose to return their product or take a repair attempt themselves. the usb reservoir caps from the Raspberry Pi board itself are removed. This will in turn result in the sign probably breaking out when replacing USB devices.
According to Upton, the defect did not come to light during testing, because in the production of the RPi 3+ two brands of current limiting switches have been used. With one brand the problems arise when using the PoE extension, while the other brand does not. The organization has only carried out tests with usb equipment that requires a lot of power with one version of the board.
Upton says that more tests will be carried out in the future to prevent similar incidents. The PoE- Hat was recently available and makes it possible to power a Raspberry Pi Model 3+ via Ethernet via a suitable switch, router or injector.