Hi,
We are currently developing our own NTN device using NRF9151 SIP LACA 1A.
I was able to flash the NTN modem firmware long with the serial modem firmware to our custom board, which worked and I was able to communicate with the board and send AT commands. After a while I flashed our own application firmware and then reverted back to the original serial modem firmware. After that I kept getting modem timeouts (see the logs below). I have measure our VDD rails, they are constant 3.3V with no dips. I have reflashed both the modem firmware and the application firmware countless times with no luck.
SEGGER J-Link V9.86 - Real time terminal output
SEGGER J-Link (unknown) V1.0, SN=1052026666
Process: JLinkExe
[00:00:00.255,462] <inf> fs_nvs: 4 Sectors of 4096 bytes
[00:00:00.255,493] <inf> fs_nvs: alloc wra: 0, fe8
[00:00:00.255,493] <inf> fs_nvs: data wra: 0, 0
*** Booting nRF Connect SDK v3.2.4-4c3fc0d44534 ***
*** Using Zephyr OS v4.2.99-9673eec75908 ***
[00:00:00.257,904] <inf> at_cmd_custom: Custom AT commands enabled with 45 entries.
[00:00:00.257,965] <inf> sm_uart_handler: UART baud: 115200 d/p/s-bits: 3/0/1 HWFC: 1
[00:02:30.259,033] <err> nrf_modem: Modem library initialization failed, err -116
[00:02:30.259,063] <err> nrf_modem: Modem library did not initialize: -116
[00:02:30.259,063] <err> modem_antenna: Modem library did not initialize: -116
[00:02:30.259,094] <inf> sm: lib_modem init: -116
[00:02:30.259,246] <err> nrf_cloud_client_id: Failed to get device UUID: -1
[00:02:30.259,277] <err> nrf_cloud_client_id: Failed to initialize client ID, error: -1
[00:02:30.259,277] <err> nrf_cloud_transport: Failed to get client ID, error -5
[00:02:30.259,277] <err> sm_nrfcloud: Cloud could not be initialized, error: -5
[00:02:30.259,307] <err> sm: Modem library init failed, err: -116
I have also test everything on a NRF9151 SMA DK which works without failure, but when moving to our own custom board I have no luck of getting it to work. For further reference, the custom board have all the pins just brought out to headers for testing with an AMS1113 as a voltage regulator for the 3.3V. I have also tested with the PPK2 as the power source, with no spikes or dips in the current delivery. Like I mentioned before it used to work on our custom board and then just stopped.
The text files have more info regarding the Chip version and serial numbers.
serial_number: 001052026666 codeAddress: 0 codePageSize: 4096 codeRamAddress: 0 codeRamPresent: false codeSize: 1048576 dataRamAddress: 536870912 infoPageSize: 4096 pinResetPin: 0 qspiPresent: false ramSize: 262144 uicrAddress: 16744448 xipAddress: 0 xipSize: 0
serial_number: 001052026666 core: Application access status: Debug access is enabled (status value: None) erase protection: false
serial_number: 001052026666 boardVersion: PCA10201 deviceFamily: NRF91_FAMILY deviceName: nRF9151 deviceVersion: NRF9151_xxCA_REV3 jlinkObFirmwareVersion: J-Link OB-nRF5340-NordicSemi compiled Jun 11 2026 13:12:28
