This tool can fix it by USB cable only so no need to disassemble the phone and no need to use JTAG boxes even.
To use this tool you need to enter APX mode ( Volume Up key + Home Key ) then connect USB cable to Phone.
After you repair the dead phone it will be into Download Mode, So you can Flash it with Original Firmware.
update the driver manually goto device manager/APX drive right click nd show d path 2 update. driver is included n d zip file.
Then run the GT-I9103 windows batch file there type 1 and press enter nd it vil start d process.
after finish it vil go into odin download mode .use odin nd update using original stock firmware below given.
Download: Samsung I9103 Galaxy R Dead Phone Fix by USB
Pit file Download