So I came across an S6-G920F that has the following behaviour :
* Doesn’t charge when plugged in.
* Starts automatically when plugged in, but stays stuck on boot logo ("powered by Android" screen).
* Can be started in Download mode when plugged in, but not in recovery mode (doesn’t pass the boot logo).
* PC detects it without any issues in Odin. Kies / SmartSwitch says "Device not supported".
* I can flash small packages (custom recoverties, bootloaders, etc.) without any issues, but not full ROM packages (3GB), it fails at any point between 15% and 99%). Immediately after it fails, Windows picks it up as "device malfunctioned". I only managed to make a successful full flash once in almost 30 attempts, and even then it got stuck on the boot logo.
* When removed from the charger, the phone shuts down almost instantly (except if after a failed flash, that takes a bit longer, ~20s).
* Leaving the phone to charge while on downloading screen doesn’t make any difference.
* The phone gets hot when downloading a firmware (not too hot in my opinion), on the right side, near the power on button.
I took it to a gms service center, the guy told me that he couldn’t figure out what’s wrong with it. He told me the phone draws 700mA when it stays on the boot logo, but there’s something that doesn’t let it power on past the boot sequence. He passed it to an electonics guy, that he couldn’t find anything either.
My best bet is that’s it’s something related to the charging parts, the charger that was used on the phone seems fake (has both english and chirilic characters on the sticker). I was told the phone died all of a sudden while gaming on it and it never started again.
Any ideas what could be the issue?