Help Bizarre behavior in a Galaxy 4

[victorboris1]

Something really weird happened to my mom's phone earlier today. It shut down mid-browsing, refused to be turned back on, and only worked when it was plugged to a charger. After it got plugged, a screen appeared with a warning stating that installing a custom OS could be potentially dangerous to any apps installed. Does anyone have any idea as to what might have happened? The phone is now working as usual. At first I thought this could have been the act of some malware, but what the heck kinda of malware would download an entire custom ROM and goad the user into installing it?

BTW: I've manually disabled OS updates, and the phone's system is only authorized to install app from trusted sources

 

[lunatic59]

My guess would be that either the battery overheated and it shut itself down or the power was being reported incorrectly and it ran out of juice.

The warning screen is 'download' or 'Odin' mode and its warning is quite dire, but not to worry, it's a normal part of the stock OS. You can access it several ways, but one includes holding a button or combination of buttons and plugging in the USB cable. Not quite sure what that combo is on the S4, but you seem to have stumbled upon it. Trust me, nothing was downloaded or installed. It's just the warning screen of stock maintenance utility.

 

[victorboris1]

My guess would be that either the battery overheated and it shut itself down or the power was being reported incorrectly and it ran out of juice.

The warning screen is 'download' or 'Odin' mode and its warning is quite dire, but not to worry, it's a normal part of the stock OS. You can access it several ways, but one includes holding a button or combination of buttons and plugging in the USB cable. Not quite sure what that combo is on the S4, but you seem to have stumbled upon it. Trust me, nothing was downloaded or installed. It's just the warning screen of stock maintenance utility.

Thanks a lot, Lunatic59. I'll give her the good news.