Some time ago, because of a bad idea of connecting USB port when battery was connected to UPS, my iCharger X8 got broken. I had that magic white smoke, you know.
Disassembled it, found a main IC got fired and had mechanical crack. Marks on the IC was scratched as on many other products from China, but they did it not very accurate, so some marks are left.

I could guess at the time that there was a word "ARM", but as its very generic word in IC's world I supposed there no chance to understand what is that. And there is also a firmware as a big unknown question. So I assembled it back and put to a shelf.
I bought a new X8. When received it, decided to take a look on that IC. This time it was scratched even more - no any marks are visible:
Yesterday when exploring different things on the Internet I've spot an IC top view and, WOW, it immediately reminded me the IC from X8 !

I edited both photos, scaled both to identical IC body size, cut black background, so we see marks from normal IC on top of my broken, and looks like they should be the same (with a shift, which we can ignore).

So, its well a know STM32F105 (or its family) in LQFP64 package.
Crystal oscillation traces - match IC's datasheet. Some 4-pins contacts on PCB look like matches JTAG interface and Vdd/Vss - also match datasheet:


Also, when you connect X8 on Linux, you see device details:
Code:
Bus 001 Device 056: ID 0483:5751 STMicroelectronics Junsi X8 USB HID
"STMicroelectronics" there is not accidentally. VID=0483 googled very often in context of ST's ICs.
So, that's the IC. Now is question - may this information help to repair my X8?
Yes, we have bin file of firmware, here is direct link to download
http://www.hillrc.com/UploadFiles/iCharger X8_V210.bin
But, I assume, it probably is encrypted/obfuscated and there is a boot loader on X8 for sure, which applies the bin file (can also form microSD card).
What to do next - I don't know. Any good idea is appreciated.
p.s. today I searched again and I've a positive feedback that a person had failed X12 and sent it somewhere to China to repair it and after ~3 months he got it back fixer/replaced. Not sure what issue he had, but it's a news for me that it was possible. So I evaluating this way too.
But wanted to share these technical IC's details here as well
p.s2 Just a note - I saw photos of disassembled iCharger 4010 Duo in the Internet and look like it uses the same STM32F105 (or its family) but in bigger - LQFP100 package (100 legs). It also was scratched on top, of course.