RPi PoE Hat Blinking Red Light


I did a recent order of a RPi 4, PoE Hat and Neo case from Core Electronics.

I had it running on a Netgear GS108PP, which is also used to power some Ubiquiti G3 Pro cameras.

It appeared to work for a couple of days. Now every time I plug it in, the RPi red LED flashes and emits a small beep which I understand is a voltage issue. Absolutely nothing has changed, and no-one has bumped it as it’s a high shelf out of everyone’s reach.

If I reconnect it via USB-C everything is perfect again.

Any thoughts on how to diagnose? I don’t have a multimeter and as we can’t have home visitors with COVID restrictions, I can’t have a friend over to diagnose just yet.



Hey Tait,

Was that the PoE or PoE+ HAT that you’ve got? I’ve heard there have been some teething issues with the older versions of the PoE and PoE+ HATs that sound suspiciously familiar to this issue. Hackaday has a few articles describing them:

If you haven’t already, be sure to send an email through to the support team over at Core Electronics by replying to your confirmation email so they can go through some troubleshooting to ensure this isn’t just an issue with your particular hardware.