Bugfix for #1024 (gsm modem re-camping) done

Michael 'Mickey' Lauer mickey at vanille-media.de
Fri Aug 21 20:48:20 CEST 2009


> today i did the rework for bug #1024 to my freerunner. First i tried to
> remove C1009 and replace it with a 22µF capacitor but i had no luck
> getting it off the board with my tools. Maybe it was glued to good and i
> have no smd tweezer iron to heat up both ends of C1009 at the same time.
> So i used the solution where i added a 10µF capacitor parallel to the
> existing one. My rework is based on [1] by Dieter Spaar.
>
> I documented my rework process with a few pictures available here [2].
>
> Now i only need a reliable testcase where i can see if the rework helped
> or not. Is there any scenario i can try to find out if #1024 is fixed or
> not?

Visit the city at noon. Shut down all processes using the modem. Use 
mickeyterm to talk with the modem. Use the following sequence of commands:

AT%SLEEP=4
AT+CREG=2
AT+CSQ=1
AT+COPS=0,0

Then, watch the unsolicited messages +CREG and +CSQ coming around for a while 
and post them here for analysis. The problem pattern is when you frequently 
receive a +CSQ: 99,99 followed after a +CREG=2, then back into +CSQ != 99 and 
+CREG=0.

:M:




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