I needed a new phone so I bought the LG K4, wanting a phone that was relatively cheap and could do the basic things (e-mail, messaging, basic surfing, music). The phone comes with little internal memory and a lot of “bloatware” (apps by LG that you don’t need) so I felt it needed some hacking. I did some surfing and was only moderately succesful, but wanted to present you the main findings and links, because some things I found didn’t work and others did. Please let me know if you find out things I haven’t listed here.
Installing ADB under Linux
You can use ADB to control your phone from a PC: reboot it, copy files, etc. If you’re on Linux, here is a great installation guide.
ADB also allows you to copy files to and from the phone. This worked better for me than MTP which gave errors and stopped working in the middle of copying files. Not sure why – maybe it’s support under Linux is limited? There is a nice tool AAFM that allows you to do the copying using ADB through a graphical interface.
Once you have ADB installed, you can remove bloatware, as described in this great recipe. You don’t need root access for this.
Inside adb shell, type
pm list packages
THen choose the app you want to uninstall, say <name> and type
pm uninstall -k --user 0 <name>
You can get more info about a particular package using
adb shell dumpsys package my.package
And yet more info here.
Managed to get into Download mode by switching off, holding the volume up button and then plugging in the USB cable to the PC. Then it says updating firmware and in the bottom you see “633A B100” (or some similar number). Then nothing happens anymore. The phone does show up as a USB device, but ADB cannot connect to it. To get out of this mode, I just removed the battery.
To communicate with the phone in this state, you use an interface called LAF, which appears to be specific to LG. Peter Wu “Lekensteyn” made a terrific set of command-line tools that allow you to interface with the phone through LAF, and you can download his tools here. Through those tools, you can execute shell commands on your phone. However, in more modern phones (such as the one I have) the commands you can run are extremely limited. If you run a command that is restricted, you will see:
Hello, I am LAF. Nice to meet you.
See this issue for more detailed discussion of this phenomenon. I wanted to use the LAF mode to root the phone but eventually just gave up.
Unclear how to put the phone in recovery mode.
Here they say: press Volume UP, Power button and Home button simultaneously
I wanted to get root access to this phone but I had no luck yet. Some forums say I should try KingRoot but that doesn’t work. It’s just an annoying app on your phone.
There is this forum post claiming they rooted the LG K4 but it looks like you require to purchase a box of some sort.
I did not have luck getting into fastboot mode either.
It seems LG phones have LAF instead of Fastboot (if I understood that correctly). I didn’t manage to get anything useful from that but here is the link. There may be a way to wipe (remove) the LAF partition, in which case the phone should revert to using Fastboot which should give you more control.