Troubleshooting • Please, I need your help about CM4 operation

I'm a hardware engineer & team leader for designing the circuit & Artwork.
Now I have been designing the Some product using Raspberry pi CM4, and I design & had a first board refer to CM4 IO Board.
When I have supply the power to first board, CM4 Module is not operating. please check what's wrong.
1. supply 4.5 ~ 5V to +5V input ports ( pin 77, 79, 81, 83, 85, 87 )
2. GLOBAL_EN ( Pin 99 ) is high.
3. and then +3.3V & +1.8V output is ok.
4. nRPIBOOT is low.
5. the PC doesn't recognize CM4.
CM4 did not ON the activation LED ( LED is not ON : LED_nACT, nPWR_LED ), any pulse is not exist.
And, the CPU is warm.

So, I tried to make low of nRPIBOOT signal.
and then, the PC recognized the CM4 for forced booting mode.

What's the problem for operating & what signals need to start CM4 module.
and please tell me check point & trouble shoot for this problem.

Thank you.

Statistics: Posted by James Ryu — Thu Mar 06, 2025 7:31 am — Replies 0 — Views 12

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