Just got a DL-X750, put in my 4G SIM (Optus, Australia), and it auto-configured worked fine.
Then, I decided to measure performance on each band, and used the preset “Set Band” AT command to set band 1.
That broke network access and I haven’t been able to get it back.
I have done every type of reset imaginable, I used “Set Band” again to try to set a known good band (eg. 28) (which didn’t actually change anything), I’ve tried flashing older firmware and Rooter, I’ve been through the Quectel AT command spec and tried anything that looks relevant (AT+QCFG=“nwscanmode”, “band”, etc), I’ve left it powered off overnight, I’ve checked the SIM still works on another router, and so on. I’e done everything but sacrifice a chicken.
But nothing fixes it. I can’t get it to connect to the network, and the preset “Request network information” AT command only ever returns:
+QNWINFO: “WCDMA”,“50502”,“WCDMA 900”,3046
Can anyone please tell me how to completely and utterly reset this device so that it works exactly as it did when I took it out of the box 24 hours ago? I’m going mad.