Dead modem



  • The lte modem in my gpy will no longer attach. I've checked the sim is current &

    DL SYNCHRO STATISTICS
    =====================
        Synchro state                         : DRX_SLEEP
        PPU SIB1 ACQ watchdog                 : 0
        Frequency Hypothesis RF  (Hz)         : -1000
        RSRP (dBm)                            : -122.70
        RSRQ  (dB)                            : -14.68
        Channel estimation state (Cell-spec.) : HIGH CINR
        Channel estimation state (UE-spec.)   : LOW CINR
        Channel estimation state (MBSFN)      : LOW CINR
        Channel estimation CINR               : 0.89
        Channel length                        : SHORT
      AGC
        AGC RX gain (dB)                      : 60.31
        RX PSD BO (dBFs)                      : -31.78
        RX PSD (dBm)                          : -125.68
        Noise level RS (dBm)                  : -119.08
        Digital gain (dB)                     : 18.00
        CINR RS (dB)                          : -3.62
      NARROWBANDS
        Last DL NB                            : Central
        Last UL NB                            : N/A
      AFC
        Frequency offset RF  (Hz)             : 549
        Frequency offset BB  (Hz)             : 0
      PBCH
        MIB received quantity                 : 63
        MIB timeout quantity                  : 0 
    

    is the AT!="showphy" return. Is there a way to pin down what the problem might be? I'm not seeing any power out of the lte antenna, is there a way to test for a failed RF transmitter in the sequans?



  • @rskoniec Mate I'm paddling hard to keep my head above water with the continual state of pycom/sequans firmware flux without trying to follow up on a single failed piece of hardware. Typical of most hybrids I reckon the RF wafer is probably heaps more fragile than the digital stuff & a glitch down the antenna feedline or on the 5v rail has cooked it. Probably the only disadvantage of having the lte integrated with the smarts on the same board.



  • @kjm Any interest from Pycom (forum chat maybe)? Definitely they should react/be interested. Maybe you should reach @Xykon, @dan, @Bettina or @Fred.



  • @cdyrssen Was never able to revive that modem, it responds to firmware upgrades but never attaches. I use that gpy still for software development since the wifi is OK.



  • @kjm It seems like I'm running into a similar issue. I was wondering if you had any luck debugging if it was the modem that actually died or a settings issue?



  • @elizar I got another gpy & it's OK, so either something has failed in the first one or there is some setting in there that's different.



  • @kjm What about "power in" of the Gpy? There is a large power consumption spike when Gpy attaches to the net.



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