Problems with the sim card and unable to do a GPIO test on the sim pins.

[DiegoMinatto]

Hello, i´m having some problems with the SIM card on my custom NRF9160 board.

if i try to use the AT%XSIM? command to check for the UUIC state i get the following response:

%XSIM: 0,9

9 – Universal Subscriber Identity Module (USIM) card failure

In order to try to discard bad soldring i´m trying to use AT%XGPIOTEST command to set the pins between high and low and check if something outputs from them, but i´m getting an error response.

What is the correct procedure for using this command ?

I also have a question about the sim card, if i have a sim card that doesn´t support either NB-IOT or CAT-M could the UUIC state of it be read ?, i´m suspecting this is the case, but i want to make sure no solder points are bad.

Edit:

I just discovered there is a production test image for modem firmware, i already flashed another modem firmware on it to try to solve some echos i had, is there any way it could be made avaliable so i can test my board ? My hardware version is nRF9160 SICA B1A

Edit 2:

I scoped the sim holder pins changing between CFUN=4 and CFUN=1, all pins have activity, 1.8V, RST, I/O go to 1.8V while CLK has a clock signal. This makes me believe eaven more that there is something wrong with the SIM card.

[Hakon]

Hello,

I scoped the sim holder pins changing between CFUN=4 and CFUN=1, all pins have activity, 1.8V, RST, I/O go to 1.8V while CLK has a clock signal. This makes me believe eaven more that there is something wrong with the SIM card.

If you think the SIM card is the problem, wouldn't it make sense to try a different SIM card to check if that works?

I just discovered there is a production test image for modem firmware, i already flashed another modem firmware on it to try to solve some echos i had, is there any way it could be made avaliable so i can test my board ? My hardware version is nRF9160 SICA B1A

I'm not 100 % familiar with the procedure of distributing PTI firmware to customers, but as far as I know this is something that needs to be approved internally before we can send the image. I will check this internally and come back to you with a more clear cut answer.

[DiegoMinatto]

Tryed with another SIM card, same problem. I asked about the SIM card because it takes me some time to get another.

[DiegoMinatto]

Tryed a different one again, same problem.

[DiegoMinatto]

Tryed on a modem from another manufacturer and it can talk with the sim card. Scoped the pins an it´s working arround 1.92V. Could the 0.12 volts difference from the NRF be causing this problem ?

[DiegoMinatto]

Solved the problem, it was never the sim card or the connections. When scoping the VCC pin on the socket i realized that there was a really fast drop to arround 1V, that´s not enought to power the sim, so i put a 100nf capacitor between VCC and GND and now communication works.