BG77 sim card of a specific manufacturer is not recognized

I am making products with BG77 and have discovered that only certain manufacturers’ sim cards do not work.

Specifically, DNP made (mark:DN) sims are not recognized.
All AX/GD/etc on the same contract were recognized with no problem.

DNP sim only: +CME ERROR: SIM not inserted.
(Of course that sim works for EC25 and BG96 and etc…)
It also occurred equally on the TE board as well as on our own board.


BG77 firmware: BG77LAR02A04_01.005.01.005

Please check the circuit, if the problem still exists, it is recommended to pull out the module SIM pin to connect the card holder

Thankyou for reply.

The TE-A board is not recognized as well.
How can I test this?

Do other modules recognize SIM cards?

Of course!

I have the same sim card test,
EG25/EC25J/BG770/BG96 and others.

Oh, I see, I suspect there is something wrong with this BG77, can you replace it with another BG77?

We also tested several BG77s,
We tested 4 units including TE-A.
All were the same and worked fine except for the DN sim.

Whether you can try to upgrade the firmware?

Possible, if firmware is available.
(I try teet:

try it again,If there are still issues, I think there may be compatibility issues with SIM cards

Thank you. I will update and report back.

I can write root->update->firehose folder right?

[2022-05-09 12:42:06:914_S:] at+qgmr
[2022-05-09 12:42:06:978_R:] at+qgmr
[2022-05-09 12:42:06:978_R:] BG77LAR02A04_01.008.01.008
DN sim (DNP Printing)
[2022-05-09 12:42:06:978_R:] OK
[2022-05-09 12:42:11:977_S:] at+cpin?
[2022-05-09 12:42:12:041_R:] at+cpin?
[2022-05-09 12:42:12:041_R:] +CME ERROR: SIM not inserted
AX sim( Thales DIS)
[2022-05-09 12:44:34:030_S:] AT+CPIN?
[2022-05-09 12:44:34:094_R:] AT+CPIN?
[2022-05-09 12:44:34:094_R:] +CPIN: READY
GD sim(Giesecke & Devrient)
[2022-05-09 12:48:48:226_S:] AT+CPIN?
[2022-05-09 12:48:48:290_R:] AT+CPIN?
[2022-05-09 12:48:48:290_R:] +CPIN: READY

Is it normal for other modules to use TE-A and DN SIM?

Of course.
BG77TE-A+board=DN NG(No1/No2/No3)/other sim ok
BG96TE-A+same board=DN(No1/No2/No3) & other sim ok

EUT1(BG77) =DN(No1/No2/No3) NG/other sim ok
EUT2(BG77) =DN(No1/No2/No3) NG/other sim ok

OK, I suggest you contact the local sales or FAE to deal with it.It should be a very troublesome problem

ok thanks!
now contact local sales…

I think test to FOTa,I want delta firmware image.

I am unable to provide DFOTA documents, so I suggest you contact the local sale and submit JIRA for solution

I understand. I will do so.

This problem is solved!
The answer was that the USIM DATA needed to be pulled up.
This is in the datasheet, but was not implemented in the BG77 EVB as well, so the EVB did not work properly, which delayed the discovery of this problem.