I am using a Samsung galaxy S2 GT-I9100 version. A few days back my phone's battery got discharged and it turned off. I charged it completely and then turned it on. It did not boot and it was stuck on the screen which shows the model of the phone. It is able to go into download mode but not into recovery mode. I removed the battery and turned it on again but all in vain. I downloaded it's official firmware from samfirmware for my country and flashed it via odin. Then odin showed the error nand write fail error. I then flashed a custom firmware but then also odin showed the same error and this time on the boot screen there was also a yellow triangle with a warning sign. I want to retrieve my data even if the phone is not revived as I had not backed it up. Please help me for heaven's sake. I would be greatly thankful.