New home assistant yellow with CM5 not powering up over PoE+ and 12V adapter

I purchased a new home assistant yellow board (POE+) and a CM5 compute module with 16GB ram + 64GB eMMC.

  1. Jumper 1 (JP1) is set to USB
  2. Jumper 5 (JP5) is set to CLS4

The board will not turn on over POE+ and multiple 12V adapters. All I see is a quick flash of the red and green LED (see picture attached. Can’t attach video). Any suggestions + tips are appreciated.

Where is your heat sink? Sticky pads?

Make sure you have a good working network cable. All conductors are needed when doing PoE.
Make sure that if using PoE, that the port is marked as PoE and that the port has PoE turned on. If using the power brick make sure to move the network cable to a non PoE port or you will damage it (either on the HA-Yellow or the switch/router, which ever you are using.
The power supply brick should be 12 VDC capable of 2 Amps or more.

After doing the reset (JP5) it has to be unjumpered!!

I took off the heat sink and thermal pads to investigate what was going on. I’m using a PoE injector with clean LAN in and power + lan out. The power injector is rated for 30W PoE (which is class 4 afaik) - hence JP5 selection.

Let me try removing the jumper after reset.

Removing the jumper(J5) after reset didn’t work.

Double check with the documentation:

Which screws did you use on the corners of the CM5? Were they labelled as CM5 on the bag?

Asking because those look like the much larger screws from the CM4 which will damage your board.

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Double check with the documentation

Yes, I’m taking a closer look at this to see if I missed something.

Which screws did you use on the corners of the CM5? Were they labelled as CM5 on the bag?

I used the ones that came with the HA Yellow. The camera angle is a bit off but it was a perfect fit for the CM5.

Thanks

@ShadowFist you’re right. The screws messed up the inductor. It was barely noticeable but I could see the damage under magnification. It’s my fault, but I wish the Nabu Casa team did a better job. I bought the HA yellow board to support the project. I’m likely to go back to my mini PC 220CAD down the drain. I wish it was clearer on the HA yellow package.

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To be fair, they warn you in the docs lordwizzard linked to, plus they label the CM5-appropriate screws in a CM5 bag. Still, I agree that a piece of paper with a huge warning should be added inside the box.

BTW, don’t throw your yellow away. That inductor costs pennies to replace - if you or anyone you know is half decent at soldering, then it’s a relatively simple fix.

I read on the related thread that it’s a 470nH 0805 SMD component. Will do some research, order the part to attempt a fix. Hopefully that Electrical Eng university degree with some
practical lab solder skills come in handy.

Will report back if I succeed.

I got myself a digital microscope to asses the damage


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Amazing this is still happening after I reported it in December 2024.

BTW you have a really sweet microscope.