SIM7080G can't find any networks.

[enzo]

I have a BK-SIM7080G whose RX and TX pins are connected to an Arduino Nano.

I have the SIM7080G connected to my PC using a USB cable for power supply.
I have a brand new SIM card inserted, and I know it works because I’ve tested it on other devices. There’s also reception so the signal shouldn’t be a problem.
I use an FPC full band LTE antenna.
I have tested some AT commands and here are their outputs:

AT
OK

AT+CPIN?
+CPIN: READY
OK

AT+CFUN?
+CFUN: 1
OK

AT+CREG?
+CREG: 0,0

AT+CMGF?
+CMGF: 0
OK

AT+CMGF=1
OK

AT+CSQ?
+CSQ: 99,99

AT+CMGS=“xxxxxxxxxxx”
Test
+CMS ERROR; 500

AT+COPS?
+COPS: 0

AT+COPS=?
ERROR

What could’ve been the problem?

[atok]

Just a cell-board hobbyist here, but if you’re sure the antenna is good and connected to the right place, I wonder what CNMP is set to, is it 13 or 38? If it’s 13 it’s in GSM mode, 38 is LTE mode.

If it’s 13 maybe that’s why you’re not seeing anything??

A Waveshare board (with a Sim7000G) I recently got had CNMP set to 13 when I powered it up, puzzled me for awhile until I set it to 38.

[enzo]

Hello, thank you for replying! Besides the antenna, could there be any other problems that have caused my module not to detect any network operator? Because CNMP returns 38 to me and it still doesn’t do anything.

[atok]

Well, I doubt this would make a difference, but I see Hologram suggests AT+CMNB = 1 (Cat-M1 rather than NB-IoT).

Then you could confirm LTE-M1 with:
AT+CNSMOD?
You should see a “7”

But again, that’s probably not the issue.

Just realized, you have a BK board, I also have a BK-SIM7000 board.

Wish I could have helped, if I think of anything else I’ll post, but that “99,99” does makes me wonder about the antenna and/or antenna connection.

[enzo]

I set the CMNB to 1 as it was originally set to 3 (both Cat-M1 and NB-IoT).

AT+CNSMOD?
returns 0.0 (no service)

So yeah, it’s still a double niner. It’s just quite unbelievable that this is brand new and the FPC antenna came along with it must be broken. I can’t find any visible damage on the antenna. Hopefully the problem is just the antenna, but it’s still best to find out where the problem is through the module’s configuration so I wouldn’t have to wait for an antenna to arrive in my doorstep–no one sells that around my place.

[enzo]

Beyond this, I checked CBC and it returns somewhere along these values:

0, 2, 3038 ~ lowest
0, 22, 3295 ~ middle
0, 43, 3565 ~ highest

I read that the SIM7080G runs at the minimum of 2.7 V, typical 3.8 V, and maximum of 4.8 V. With the USB connected between the module and my PC, it provides 3.3-3.5 V. Could the power supply be the problem? Because as I said, it’s operating within the rating, however it falls between 2.7 and 3.8, but never 3.8 and beyond.
(2.7 < V < 3.8)

[atok]

Voltage check is a good idea … for comparison I powered up my BK-7000 board with a hologram sim, did the CBC command about a dozen times over 10 minutes, and got right around 3.6 volts each time. A bit on the higher side compared to your voltages, but doesn’t seem extreme.

[Dom]

Can you set the error logging to verbose, the fact cops returned ERROR instead of an empty list is suspect. Try AT+CMEE=2

I am also suspect that the signal quality is showing no signal. Can you see how the registration process is going with AT+CREG? and AT+CEREG?

[Sergio_Contro]

First check power supply, don’t operate with notebook or laptop USB. Not use dupont cina wirings. My experience comes from SIM800 module: if well powered it connects without any AT commands from the board because inside own a user profile that starts at boot.