FONA CHIP SEEMS FAULTY

Adafruit cellular platform - SMS and IoT over celluar

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ghuser
 
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FONA CHIP SEEMS FAULTY

Post by ghuser »

Hello,
One of the FONA (Adafruit FONA - Mini Cellular GSM Breakout - SMA Version (v1) [ID:1963]) chips i bought from Adafruit seems to be faulty. Please find screenshot. I am using hardware serial with the Fona chip connected to Arduino Mega Chip.
Hardware serial communication seems to be okay as seen in the screenshot below. The battery is also harged (>80%) also found in screenshot.
We have used the FONAtest sketch from Adafruit Fona Library and it was configured to use hardware serial and also the APN also was configured correctly.
However, the problem is that the chip cannot register to the network. The network light keeps blinking every 2 seconds.
And in the serial console, it can be found that the status of network is:
FONA> n
---> AT+CREG?
<--- +CREG: 0,3
Network status 3: Denied
Note: I have used the same SIM (2G Enabled) card in other FONA chips and it works perfectly.
And it stays so indefinitely.
Hence the Fona chip cannot do any operations like calling, sending or reading SMS and also GPRS cannot be turned on.
Normally, we are used to the functionalities of the FONA chip since we have bought so many from Adafruit but we are not being able to resolve this issue. Could you please advise.
Thank you in advance
Attachments
Connections of the FONA
Connections of the FONA
fona setup-min.jpg (727.83 KiB) Viewed 1351 times
Network Status and Battery level
Network Status and Battery level
screenshot3fonabattery.png (135.83 KiB) Viewed 1351 times
FONATEST example
FONATEST example
screenshot2fona.png (154.2 KiB) Viewed 1351 times

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adafruit_support_mike
 
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Re: FONA CHIP SEEMS FAULTY

Post by adafruit_support_mike »

ghuser wrote:FONA> n
---> AT+CREG?
<--- +CREG: 0,3
Network status 3: Denied
That means the hardware is working, but the cell tower isn't letting the FONA connect. You'll need to talk to your service provider about that.

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ghuser
 
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Re: FONA CHIP SEEMS FAULTY

Post by ghuser »

Hello Mike,
I talked with our telecommunication partner and gave them the "I M E I" but they said this is not related to them as the hardware itself cannot connect to them. And with all other fona devices it did work well and did not require any intervention from their side.

Could you please advise why the fona itself cannot connect to a cell tower.
Does the fona require any additional configuration from the telecommunication company to be used?
Because we buy lots of fona from Adafruit for our products and they did not require additional configuration. Has anything recently changed in the fona chip which requires this?
Let me know if you wish to do a remote debug as well.

Thank you for your help
We are concerned because we plan to use a large number of FONA chips in our hardware.

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adafruit_support_mike
 
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Re: FONA CHIP SEEMS FAULTY

Post by adafruit_support_mike »

You shouldn't need to do anything with that FONA that you don't do with any of the others.

Try swapping SIM cards with one of the devices that connects normally and see if the connection problem stays with the FONA or follows the SIM.

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ghuser
 
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Re: FONA CHIP SEEMS FAULTY

Post by ghuser »

Hi Mike,
I already did that. I even tried the same SIM card in another similar fona chip i bought in the same order and it works perfectly but not with this one fona device.
I also tried a different 2G SIM operator and changed APN but still it does not connect.
Thank you

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adafruit_support_mike
 
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Re: FONA CHIP SEEMS FAULTY

Post by adafruit_support_mike »

Hmm.. does the misbehaving FONA show the same LED patterns as the ones that do connect?

The 'network status: denied' message suggests communication with the tower.

Also, if you're using 3G, are you also using an external antenna?

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ghuser
 
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Re: FONA CHIP SEEMS FAULTY

Post by ghuser »

Hello Mike,
No, it does not show same pattern as correct ones can connect to network and i can turn on GPRS. However with this one the red light just keep blinking approximately every 1 second indefinitely. I am using 2G and i am using this antenna (Slim Sticker-type GSM/Cellular Quad-Band Antenna - 3dBi uFL) from Adafruit.
Thank you

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adafruit_support_mike
 
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Re: FONA CHIP SEEMS FAULTY

Post by adafruit_support_mike »

Thank you. The LED behavior supports the idea of a bad connection to the tower.

Could you post a photo of the SMA antenna connector at the edge of the board? I want to double-check the solder joints.

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ghuser
 
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Re: FONA CHIP SEEMS FAULTY

Post by ghuser »

Hello Mike,
Here it is.

Thank you.
Attachments
solder joint sma-min (1).jpg
solder joint sma-min (1).jpg (760.52 KiB) Viewed 1281 times

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adafruit_support_mike
 
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Re: FONA CHIP SEEMS FAULTY

Post by adafruit_support_mike »

Hmm.. the center and the one one on the left look marginal. Try reheating and reflowing those and see if it has any effect.

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ghuser
 
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Re: FONA CHIP SEEMS FAULTY

Post by ghuser »

I have tried reheating and reflowing as you advised but it still cannot do any operations like calling, sending or reading SMS and also GPRS cannot be turned on.

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Re: FONA CHIP SEEMS FAULTY

Post by adafruit_support_mike »

Thank you for trying.

Scanning back through the posts above, it looks like this is one unit that you've tested in parallel with others that work normally. Ruling out antenna problems eliminates most of the things that can be modified, so let's try a new unit.

Send a note containing a link to this page and your order number to [email protected]. The folks there will get you a replacement.

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