Now i tried factory data reset and clearing cache in Power and Volume + key mode. It did not work. I tried applying update (two different roms, one custom pakistani rom and other was normal g510-0200 rom) in the same mode but it shows installation aborted.
I tried Forced Firmware Update mode too. I placed update.app file in the sd card and restarted cell phone by holding Volume+, Volume- and Power key. In that mode, it shows unpacking Step 1/2 for a while and then instead of installing, it shows Update Failed.
Error log shows this:
filename = /mmc1/dload/update.app call RCV_MODULE_END_EVENT failed,module = OEMSBL_VER_LIST CMD=0xf,moduleaddr = 0xd2000000, len_tmp=0x4000
I have tried everywhere and I'll be really greatful if anyone can sort this out for me.