Please follow these steps:
In the first step turn off the smartphone by holding the Power button for a few seconds.
Then choose Volume Down and Power keys together for a few moments.
When the LG logo pops up release the Power key, keep pressing the Volume Down and then press the Power button again.
Release all buttons when Factory data reset appears.
Now select "Yes" two times by using Volume keys to scroll down and the Power button to confirm that.
My LG Stylo 4 is doing the same thing. The battery stays on 0% after being on original charger for hours. Phone just keeps starting, giving that 'unbootable' msg, screen goes black and restarts with same msg. It just loops this cycle.
Trying to reboot with reset[power and vol.down], says 'recovery mode loading... then shuts down to start back up with same problem. Had this phone only 5-6 months, never dropped, no water. Just dead battery. Only used phone maybe 6 times since had it.
I am beyond frustrated because its my biz number and i have 4 lines with you guys. Need HELP ASAP.
BTW, never saw 'factory reset' screen. Phone just went black to start loop all over again.
I have been paying for this line from day one, and the phone is not working. Wasting money paying for phone that will never ring. Losing money from biz every day, too.