My phone won't boot up suddenly. Please help, thanks!

[masterton]

It is Samsung Galaxy Note 2 (GT-N7100), unrooted, stock ROM.
It always stuck at the Samsung Galaxy Note 2 logo screen.
I can boot to recovery mode and download mode.
What should I do to save my phone? Thanks a lot.

I tried to flash by using download mode but I got these errors.

<ID:0/003> Added!!
<ID:0/003> Odin engine v(ID:3.1205)..
<ID:0/003> File analysis..
<ID:0/003> SetupConnection..
<ID:0/003> Initialzation..
<ID:0/003> Get PIT for mapping..
<ID:0/003> Firmware update start..
<ID:0/003> SingleDownload.
<ID:0/003> sboot.bin
<ID:0/003> FAIL!
<ID:0/003>
<ID:0/003> Complete(Write) operation failed.
<OSM> All threads completed. (succeed 0 / failed 1)

When repartition is checked:

<ID:0/004> Added!!
<ID:0/004> Odin engine v(ID:3.1205)..
<ID:0/004> File analysis..
<ID:0/004> SetupConnection..
<ID:0/004> Initialzation..
<ID:0/004> Set PIT file..
<ID:0/004> DO NOT TURN OFF TARGET!!
<ID:0/004> Can't open the specified file. (Line: 1831)
<OSM> All threads completed. (succeed 0 / failed 1)

The following errors displayed when I booted to recovery mode:

Android system recovery < 3e >
KOT49H.N7100ZSUFNL1

E:failed to mount /efs (No such file or directory)
E:failed to mount /system ((No such file or directory))

# MANUAL MODE #
--Appling Multi-CSC
E:failed to mount /system (No such file or directory)
can't mount '/system' (No such file or directory)
E:failed to mount /cache (No such file or directory)
can't mount '/cache' (No such file or directory)
E:failed to mount /cache (No such file or directory)
E:can't mount /cache/recovery/last_recovery
E:failed to mount /data (No such file or directory)
E:can't mount /data/log/recovery_log.txt
E:failed to mount /system (No such file or directory)
E:failed to mount /cache (No such file or directory)
E:can't mount /cache/recovery/log
E:can't open /cache/recovery/log
E:failed to mount cache (No such file or recovery)
E:Can't mount /cache/recovery/last_log
E:can't open /cache/recovery/last_log
E:failed to mount /cache (No such file or recovery)
E:can't mount /cache/recovery/last_install
E:Can't open /cache/recovery/last_install
E:failed to mount /cache (No such file or recovery)

 

[boosted1g]

You will have to research the exact things needed for yoru phone and download the tools/software.

You will need Samsung USB drivers for your phone, ODIN software, newest software update of your Note (make sure it is the right one for your model and your carrier).

Then you will plug your phone into PC, enter recovery mode, open ODIN software and push the new image to your phone.
This will overwrite your current OS so everything not on your SD card will be overwritten and lost.

 

[masterton]

You will have to research the exact things needed for yoru phone and download the tools/software.

You will need Samsung USB drivers for your phone, ODIN software, newest software update of your Note (make sure it is the right one for your model and your carrier).

Then you will plug your phone into PC, enter recovery mode, open ODIN software and push the new image to your phone.
This will overwrite your current OS so everything not on your SD card will be overwritten and lost.

I tried factory reset in recovery mode. It failed.
Then I used ODIN software to flash my phone. The first two error messages were given when I tried so.
What else should I do now?