Compute Module • CM5 is not being detected as mass storage

I have the CM5 with IO board (supplied together in dev kit). Plugging in USB & powering on does not show device as mass storage device (`/dev/sdX`).

This github issue seems to have tracked a similar issue with the CM4 but the conclusion was a USB cable problem. I am using the cable supplied with the dev kit.

One thing that puzzles me in the docs is step 3 of "Set up the IO Board":

Connect a cable from USB-C slave port J11 on the IO board to the host device.

Looking at the board, this is the power input. This contracdicts later instructions to only power on the board when (data) usb is connected & rpi is running on host.

All in all, what am I missing?

p.s. Ubuntu RPI boot build seems a little old?
```
» sudo rpiboot
RPIBOOT: build-date Jan 31 2022 version 0~20220315+git6fa2ec0+nowin-0ubuntu1
Waiting for BCM2835/6/7/2711...
```

Statistics: Posted by sspinn — Sat Aug 09, 2025 10:05 pm

---