Activation Issues with B504

Hardware
1

I'm running into a persistent issue with several B5SoM units in Canada. The problem specifically occurs during initial activation - certain units never successfully connect to the network and remain stuck in a perpetual green flashing state. This is happening despite being in an area with excellent cellular coverage, including Rogers (which I understand is Particle's highest priority network in Canada).

I'm testing these on an M.2 SOM Eval Board 1.2, and have ruled out power-related issues. This has affected multiple different units, though interestingly, once a unit does successfully connect initially, it works perfectly fine thereafter. There's seemingly no differences between units that connect and those that don't, all in the exact same location.

The modem appears to initialize correctly and the SIM is properly detected. However, the device gets stuck in a network search state and never successfully registers. The logs consistently show AT+QCSQ returning "NOSERVICE" and the registration status remaining at "2,2" (searching).

I've attempted multiple restore and reactivation cycles, but the behavior persists across affected units.

All SIMs appear active.

I can provide the full logs if they would be helpful in diagnosing the issue. Any guidance would be greatly appreciated, particularly if there are troubleshooting steps beyond the standard restore/reactivate process that might help resolve this.

1 Like
2

The SIMs need at least 3-5mins to cycle their carrier profiles - so giving the device some time to soak and cycle profiles should allow them to connect.

How long have you seen the devices attempt to connect?

1 Like
3

With some devices it's been close to 24 hours of flashing green and these log outputs. The devices that do connect seem to do so within a couple of minutes.

4

Ok, I'll send you a DM.

5

I'm noticing this issue on three additional units; I've swapped out antennas, tried different power setups, confirmed no physical damage to uF connector, etc to no avail.

The logs are the same for all three, some variation of:

0000369865 [ncp.at] TRACE: < OK
0000369866 [ncp.at] TRACE: > AT+QCSQ
0000369868 [ncp.at] TRACE: < +QCSQ: "NOSERVICE"
0000369868 [ncp.at] TRACE: < OK
0000384869 [ncp.at] TRACE: > AT+CEER
0000384871 [ncp.at] TRACE: < +CEER: 0,-1
0000384872 [ncp.at] TRACE: < OK
0000384872 [ncp.at] TRACE: > AT+CMEE?
0000384874 [ncp.at] TRACE: < +CMEE: 1
0000384875 [ncp.at] TRACE: < OK
0000384875 [ncp.at] TRACE: > AT+CREG?
0000384877 [ncp.at] TRACE: < +CREG: 2,2
0000384878 [ncp.at] TRACE: < OK
0000384879 [ncp.at] TRACE: > AT+CEREG?
0000384880 [ncp.at] TRACE: < +CEREG: 2,2
0000384881 [ncp.at] TRACE: < OK

About 80% of the B504s we have activate without issue and are deployed successfully, but it seems there are units that randomly have this issue which does not appear to have a solution.

There's excellent LTE/3G coverage from all supported carriers; I'm in an urban location in Saskatchewan, Canada.