reTerminal DM - Dual Ethernet PCIe Port Expansion killed reTerminal

Products & Technology Raspberry Pi
1

Been using a reTerminal DM for about a year now and it has been amazing. I now need to add dual ethernet ports to the device. When I added this expansion board and repowered the device it no longer is responsive. The act/power light are on solid. The act no longer flickers.

I tested voltages on the various headers and everything is within spec.

When I try connecting using the rpiboot nothing happens. I can try replacing the cm4? but the root cause seems to be the pcie add on board?

Has anyone else experienced this? Wiring issue with the harnesses?

Any help appreciated.

2

Hi there,

and welcome back :grin:

So can you post a picture of it? Where is the power source from , the Pie or external?

HTH
GL :slight_smile: PJ :v:

3

External 24vdc 5a Din Rail

20250703_121347
20250703_1213471920×2560 406 KB

4

Hi there,

Awesome, So everything Looks in order :+1: as I can see.
so ACT LED solid (not flickering) = the CM4 isn’t successfully booting.
No rpiboot response = USB fallback boot mode is likely disabled or CM4 is hanging at early boot.
Voltages fine = power delivery is likely okay.

  • Remove PCIe card
    → Power on the reTerminal without the PCIe expansion board.
  • If it boots now, that confirms the add-on is the issue.
  • Check rpiboot mode with jumpers
  • Some reTerminal units require the USB boot jumper or DIP switch enabled. Check if that’s properly set.
  • Try a different PCIe card (like a known-good USB3 or SSD card).
  • Inspect the PCIe connector and CM4 socket
  • Look for bent pins, misalignment, or solder shorts on the expansion board.

I did see a mention of EmmC corruption is some other old threads, but if you remove it and it comes back as normal, next up is test the Slot with the SSD or something.
Maybe another Seeedineer will chime in and give some guidence.
Hit the WiKi and see if I missed anything also. :wink: :+1:
LMK

HTH
GL :slight_smile: PJ :v:

they are a great product though, just needs more refinement. IMO.

5

Thanks for all the feedback. I have removed the add on board and tried to connect with no luck.

I have reached out to seeed to see if they can help.

1 Like
6

Hi there,

No problem, Good call… I believe the power section to be the units achilles heal. maybe need more regulation, it’s like any extra current draw, hurts the CM4 module but nothing else? I use the same or similar Single PCIE to NNIC in my Pfsense router to get that one more Network port. Works excellent and throughput is decent. They will get you sorted I know it works, they demoed it at the show a while ago… :crossed_fingers:

HTH
GL :slight_smile: PJ :v:

I hope they do a "Color CM5 " unit :yum: :+1:

7

Disconnect the PCIe board, re-power the reTerminal DM.
If the ACT LED resumes blinking and HDMI/UART becomes responsive, it confirms the PCIe board is the cause.

1 Like