RPI CM4 doesn't boot

[reyntjensm]

I made a design with a rpi CM4 module connected to my own PCB. As far as i know all the connections to the CM4 module are correct. Sadly enough the CM4 doesn't power/boot up. I can measure 5V at some caps on the CM4 module. The other caps show no voltage at all. I don't understand why the CM4 module doesn't generate the 3,3V rail. The troubleshooting guide on the RPI website doesn't help me also. I've checked the Global_EN signal and this is high, the guide says if 5v is available the other rails should power up. So i don't see any reason why the CM4 module doesn't generate it's own voltage rails. Any advice on this?

[dmendesf]

Do you have a carrier board to test the CM4? Can you share schematics/photos of the assembly?

[SiliconWizard]

A schematic of your own board would help.

Have you connected the Global_EN pin to anything externally?

[fchk]

Use the CM4 IO Board as a reference.
https://datasheets.raspberrypi.com/cm4io/cm4io-datasheet.pdf

You will need more than only 5V in order to boot the CM4. Look it up in the schematics on pages 9++.

fchk

[eugene]

According to the CM4 Datasheet, GPIO_VREF must be connected to either 3.3V or 1.8V. See page 9 and 10. Also the table on page 19.