EC25-EC modem unstable

Technical Support for Routers 4G LTE, 5G NR, USB modems
1

Hello. I recently bought a Quectel EC25-EC USB modem from Aliexpress for my GL-MT3000 (on the latest firmware). Specifically from this seller:

https://www.aliexpress.com/item/1005006338902261.html?spm=a2g0o.order_list.order_list_main.29.77cb18028xz7LN

The modem seemed working fine for the first time, but it has a weird behavior. If I let the system run for a while and I power cycle the router, it's unable to connect to the modem anymore. If I remove the modem, reboot the system, wait until it's up, then insert the modem, then it will be connected again. When I simply reboot the system (while the modem is connected), then everything is fine, the router reboots, and the modem is reconnected. However If I just pull the power plug and then power the router again, it cannot see the modem as if it would be not connected at all (even if I try to disconnect and connect again). But the weirdest thing is that it's not always the case. Sometimes the modem is working fine even after power cycle. If someone let me know what log I should pull (and how) when the modem is in a "not reconnected" state, then I'd be happy to help with the investigation.

Thank you guys in advance,
B.

2

Does the EC25 have another power supply?

4

Nope. It's powered by the router. It has no connector for external PSU, only the USB A connector. When it's working, it's stable. The problem arise when cycling the power of the router.

5

It seems that the usb power supply is later than the startup time of the external modem
Try pulling the usb power down and up again

ssh 192.168.8.1
echo 0 > /sys/class/gpio/usb_power/value
echo 1 > /sys/class/gpio/usb_power/value
6

Thank you for the advice! I'll test this solution Today, and let you know if it does the trick. I assume putting these commands to the /etc/rc.local is legit... Eg. like this:

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7

So the situation is getting even stranger... I tend to think that something is wrong with the Quectel EC25-EC modem I recently bought, because after a while, the router disconnects it, even if it was successfully connected upon boot. In this case pulling the cable physically or issuing the command you shared above doesn't help. Moreover I have a Quectel EM06-E USB modem as well (which is rather bulky, this is why I wanted to use the EC25-EC). So when the router disconnects the EC25-EC and I'm trying to replace it with the EM06-E, the router doesn't connect to that one either, unless I'm rebooting it. I have to admit that in general the EM06 is working flawlessly with the router, so I haven't experienced anything similar like with the EC25. It's available right after boot, and the router has never disconnected it. But here's the twist. If I connect the incriminated EC25 to my laptop or to my desktop PC, it works flawlessly (I'm using LMDE). So I tend to think that something is wrong with the EC25 (since the router is working perfectly with the EM06), but it's still disturbing that I can only replicate this issue with the GL.Inet router and nothing else.

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IMG_84722268×4032 1.34 MB

8

IMG_8471
IMG_84715712×3213 2.67 MB

9

image
this is EC25-EC?
Can you export logs when the connection is successful and then disconnected?
I think it may be a usb power supply problem

10

Nope. This is the EM06. The EC25 is the small one I linked above (Aliexpress link). If you tell me which commands I should issue in the terminal, I can share the logs of course.

11

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12

Hello. Logs attached...
logread_EC25_working.tar (173 KB)
logread_EC25_disconnected.tar (176.5 KB)

13

https://dl.gl-inet.com/router/mt3000/
Can you try 4.6.2?
I'm not sure if this is a problem caused by disabling usb3.0

14

Hello. I’ll try later Today. BTW the same issue occurs with the EM06 as well, but it works for hours before it happen. I think it’s rather a software or hardware issue with the router. These modems working flawlessly with my PC.

15

The same issue with 4.6.2.

16

Is the mt3000 using an original adapter?
Have you installed any plugins?

17

Yes it is and no I haven’t installed any plugins. I only configured the Wireguard client, everything else is more or less out of the box.

18

Technical Support via GoodCloud.tar (192 KB)
Can I see it remotely?
It looks like the usb power supply is not stable for them

19

Should I upgrade the device back to the latest firmware before I do this cloud thing?

20

Hello.

It's done. I just sent a PM with the connection details. It's a vanilla install of the latest firmware. I haven't modified anything except I connected the modem and set my timezone.
Please let me know if you need anything else.

Thanks,
Balazs

21

Hello.

Any news on your investigation?

Thanks,
B.