Sierra MC7455 + BFT4KB

4G/5G/LTE discussions
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desro.ca
Posts: 2
Joined: Wed Apr 08, 2026 4:35 pm

Sierra MC7455 + BFT4KB

Post by desro.ca »

Hi!

Newly using BFT4KB here. We have been using PCEngines products for a while, then Corpshadow's FW series (might be Protectli related).

We always have been using Sierra MC7455 LTE cards.

Now it doesn't seem to work in a BFT4KB : LTE modem is recognized, I am able to send commands via the serial port. However when looking for the SIM status using AT+cpin? command, I always get the message "+CME ERROR: SIM not inserted"

OFC I tried both SIMs slots. I did reboot the unit after swapping.


Any ideas?
desro.ca
Posts: 2
Joined: Wed Apr 08, 2026 4:35 pm

Re: Sierra MC7455 + BFT4KB

Post by desro.ca »

Found more info (no thanks to Google on that one).

System board hardware manual : https://boingfire.com/wp-content/upload ... l_V1.0.pdf

There is a total of 4 SIM slots on that board. SIM3 and SIM4 (visibles ones) are connected to WiFi/4G MPE1/MPE2 ports
The M.2 B-Key is connected to SIM1 slot (front, underside)
The MSATA2/USB slot is connected to SIM2 (back, underside, board needs to be removed)

Here you go!
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