One EC25 module connects fine, the other can’t register to network – possibly fake?

Technical Subjects
1

Hi,
I have two EC25 modules. One of them works perfectly and connects to the network without any problem.
The other one doesn’t register to the network at all.

The label on the back of the module is incomplete, and I opened the shield — the internal PCB layout under the shield looks different from the working one.

Could this module be a fake or a clone?
What can I check to confirm whether it’s genuine or not?
Which AT commands or information should I provide here to help identify the issue?

IMG_20251016_194053638~2
IMG_20251016_194053638~21920×2550 286 KB

Thanks in advance!

3

The working module’s firmware version is EC25EUXGAR08A09M1G,
and the non-working one originally had EC25EUXGAR08A13M1G.
I even upgraded it to EC25EUXGAR08A19M1G, but it still can’t register to the network.

Could this problem be related to the firmware version or hardware difference?
I’m planning to use these modules in the Middle East region.

Any advice on how to verify if the module is genuine or what might be wrong would be greatly appreciated.

Thanks in advance!
[2025-10-16 20:56:58:008_S:] ATI
[2025-10-16 20:56:58:016_R:] ATI

[2025-10-16 20:56:58:016_R:] Quectel
[2025-10-16 20:56:58:016_R:] EC25
[2025-10-16 20:56:58:016_R:] Revision: EC25EUXGAR08A19M1G

[2025-10-16 20:56:58:016_R:] OK
[2025-10-16 20:56:58:034_S:] AT+QURCCFG=“URCPORT”,“usbat”
[2025-10-16 20:56:58:035_R:] AT+QURCCFG=“URCPORT”,“usbat”

[2025-10-16 20:56:58:046_R:] OK

/* Use AT+CPIN? to query the SIM card status : SIM card inserted or not, locked or unlocked */
[2025-10-16 20:56:58:056_S:] AT+CPIN?
[2025-10-16 20:56:58:065_R:] AT+CPIN?

[2025-10-16 20:56:58:071_R:] +CPIN: READY

[2025-10-16 20:56:58:071_R:] OK

/* Use AT+CIMI to query the IMSI of SIM card */
[2025-10-16 20:56:58:087_S:] AT+CIMI
[2025-10-16 20:56:58:088_R:] AT+CIMI

[2025-10-16 20:56:58:097_R:] 432200201201707

[2025-10-16 20:56:58:097_R:] OK

/* Use AT+QCCID to query ICCID number of SIM card */
[2025-10-16 20:56:58:115_S:] AT+QCCID
[2025-10-16 20:56:58:121_R:] AT+QCCID

[2025-10-16 20:56:58:128_R:] +QCCID: 89982023501412017074

[2025-10-16 20:56:58:128_R:] OK

/* Use AT+CSQ to query current signal quality */
[2025-10-16 20:56:58:137_S:] AT+CSQ
[2025-10-16 20:56:58:148_R:] AT+CSQ

[2025-10-16 20:56:58:148_R:] +CSQ: 99,99

[2025-10-16 20:56:58:148_R:] OK

/* Use AT+CREG? /AT+CGREG? to query the network registration status. */
[2025-10-16 20:56:58:166_S:] AT+CREG?
[2025-10-16 20:56:58:172_R:] AT+CREG?

[2025-10-16 20:56:58:177_R:] +CREG: 0,0

IMG_20251016_180424253
IMG_20251016_1804242531920×1446 174 KB

4

Dear @madelat ,

Thank you for the detailed information and photos.

Based on the AT log you shared, this is not a firmware-version issue. The non-working module is not registering because it is not detecting any usable RF signal. Specifically, AT+CSQ returns 99,99 and the registration status remains +CREG: 0,0. When the module cannot measure signal (CSQ 99,99), it will not be able to camp on a cell or proceed with network registration.

Also, a different PCB layout under the shield does not by itself indicate a fake module. Hardware layout and shielding can vary between genuine production batches and revisions. The definitive way to confirm authenticity is through traceability identifiers (IMEI/SN/PN) and verification via the official sales channel.

To confirm the root cause and close this out, please provide the following outputs from both the working and non-working modules, tested in the same setup (same host board/slot, same antenna/cable, same location, same SIM if possible):

Identification / traceability
ATI
AT+QGMR
AT+CGSN (or AT+GSN)
Clear photo of the back label showing the full PN and SN

Registration and radio status
AT+CFUN?
AT+COPS?
AT+CEREG?
AT+QNWINFO
AT+QENG=“servingcell”

If the non-working module continues to show CSQ 99,99 while the working module shows a normal CSQ value under the exact same antenna/setup, then the conclusion is definitive: the issue is in the RF path (antenna/connector/cable) or the module hardware itself, and it will not be resolved by upgrading firmware. With the IMEI/SN and purchase source, we can also help you verify the module’s traceability through the proper channel.

Best Regards,
Aghelan