OK, I found a solution myself
Phone did not start because of FFS_C corrupted filesystem. This is log from PapuaUtils:
---
Booting in "Normal Mode"...
Press P.ON !
AutoIgnition...
Transm. Boot...
Booting in Normal Mode OK
Wait to power on phone ...
Phone was OFF by error :
EXIT: 0260:5BCE
FILE:
fmexecc
CPSR: 60000010
CepId: 46FF
ExitString:
FFS_C
---
So, I found a good fullflash of same version as mine (v12 lg1), and I replaced FFS_C area (2E0000-4DFFFF) from good one to mine with Winhex. After that I wrote it back to phone with x65flasher. Last step was to repair EEPROM blocks 76, 5008, 5009, 5077, 5121, 5122, 5123 with x65PapuaUtils (BIG THANKS to Papua!!!). That was about it, phone back to life!
Hope it will help somebody...
(OFFTOPIC) @SST-GSM: It's not about money, I wanted to learn about mobile internals also. Ahhh, one last thing: Go eat your ****ty program! I would gladly pay "about 5-10