• u/lukmly013 💾 (lemmy.sdf.org)@lemmy.sdf.org
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    12 days ago

    Yep, it does fit into a pocket.

    BTW, your Power Armor 13 is also MTK based. Good chance you can get into the hidden menu by dialing *#*#3646633#*#* (it opens automatically without clicking dial).
    But be warned, some settings may not be safe to mess around with.

    About the band selection menu, it looks like this:

    There’s a lot of things in MTK Engineer mode, and a lot of them should probably not be accessible for a good reason. Most manufacturers seem to block access to this. Oppo and Realme even seem to encrypt it so that it’s only accessible to service personnel.
    Preview of the main menu:

    Unfortunately, I couldn’t find any documentation for this, and there’s many things I am too scared to click. Something could make illegal transmissions, others could be some non-resettable options, who knows. Yes, there is some factory reset resistant stuff I found. If there’s one, there can be more.
    For example, the MTU value setting:

    I’ve also seen a post from someone who ran some automatic full device test in a hidden menu on some Chinese phone, it turned out part of the modem test was dialing some number, 911 was the number, it turned out…

    Anyway, one illegal thing some of these are/were able to do is change IMEI. The AT command tool here doesn’t work, but on some devices it does. And there’s also a command to change the IMEI.
    I found this on XDA, it seems some devices possibly even simplified that process:

    Anyway, there’s also something step above band selection, specific cell tower selection:

    I didn’t find that particularly useful, but I did find out the cell tower range limit in a city seems to be 1km. Makes sense, you don’t want devices screaming at some distant overloaded tower when the city is full of them. Maybe they can even have lower latency that way, I don’t know. I don’t know how the timing works.

    Oh, it seems I can transmit garbage on WiFi channels:

    But I also found a way to force VoLTE registration even though my carrier doesn’t provision this device. EngineerMode -> Misc feature config -> hVoLTE device mode -> hVoLTE (even when already selected).
    I was actually able to make a phone call in 4G only this way. But it has to be done every time the phone is connected to the network.