How To: Unlock NAND on the HTC Evo 4G

THIS IS UNNECESSARY! IF YOU USED THE NEW HOW TO ROOT METHOD IT AUTOMATICALLY UNLOCKS NAND FOR YOU:

HOW TO ROOT THE HTC EVO (UNREVOKED PROCEDURE)

I. Before You Begin

1. You MUST do our How To Root the HTC Evo 4G procedure, then come to this one to unlock NAND.

2. You would unlock your NAND to load certain custom ROMs (like Cyanogen’s).

II. Setup ADB

1. Do our How To Setup ADB procedure. Once you can see your device’s serial number at the end of the procedure, then come here to continue.

III. Perform a Nandroid Backup

1. Turn off your phone.

2. Turn it back on by holding down volume down and power until hboot mode comes up. Use the volume down button and click power to select recovery.

3. Once the phone boots into recovery scroll down using the volume down buttons to Nandroid and select it. Then select backup and wait for it to finish backing up.

4. Once it is done, select Reboot System Now and wait for the phone to boot back to the normal home screen.

III. Unlock the NAND

1. Download the following files and save them to your computer.

PC36IMG.zip
mtd-eng.zip
flash_image.zip
recovery2.img (if this downloads as recovery.img, simply rename it to recovery2.img)

2. Plug the phone into the computer via USB and mount the sd card so we can transfer files to it.

3. Unzip the mtd-eng.zip and flash_image.zip file and put their content on to the root of the sd card (not in any folders on the sd card just on the sd card itself).

4. Copy the recovery2.img file and the pc36img.zip file (do NOT extract it, leave it as a .zip) to the root of the sd card (not in any folders on the sd card just on the sd card itself).

5. Unmount the sd card on your phone. Then go to Settings > Applications > Development > and make sure USB Debugging is ON.

6. Open the command prompt on your computer by going to the start menu and typing cmd and hitting enter.

7. Type the following into the command prompt with hitting enter at the end of each line:

cd\
cd c:\AndroidSDK\tools\
adb shell
su
cat /sdcard/flash_image > /data/flash_image
chmod 755 /data/flash_image
/data/flash_image misc /sdcard/mtd-eng.img

8. Once that is done, turn off the phone.

9. Turn the phone back on by holding down Volume Down and Power until HBoot mode comes up.

10. It should automatically find the PC36IMG file and ask you to confirm. Select yes and wait for it to finish flashing.

11. When it asks you if you want to reboot select yes. (It takes a long time to load up the first time, be patient).

12. Once the phone reboots to the regular home screens, make sure it is still plugged into the computer and go back to the command prompt on your computer.

13. Type the following into the command prompt with hitting enter at the end of each line:

cd\
cd c:\AndroidSDK\tools
adb shell
su
cat /sdcard/flash_image > /data/flash_image
chmod 755 /data/flash_image
/data/flash_image recovery /sdcard/recovery2.img
reboot recovery

14. Once the phone reboots into recovery mode, navigate with the volume buttons and use power to select Wipe Data and select it.

15. Select reboot system now and you are all set! Now you can go to our procedure below and flash any Evo ROM you want.

IV. (Optional) Load a Custom ROM

1. Head over to ourย How To Load a Custom ROM on the HTC Evo 4G procedure.

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  • Kmoon

    Refuses to find “cat /sdcard/flash_image > /data/flash_image.” No matter how many times I enter it in, it just keeps telling me that no file or directory exists, and I don’t have a clue about what else to do. It’ll do everything else, just not the prompt I mentioned :(…

    • Kmoon

      Okay, after going at it for a while, it finally found it. Not sure why because I didn’t do anything differently, but it’s still all good. Thanks for all your how-to-do guides!

  • Matthew

    it says when i do the hboot and wait for the pc36img to update it fails and says “Main version is older!, Update Fail!” and then asks if i wanna do a reboot or not.

  • Sam

    can’t get passed the first set of cmd prompts. help.

  • NxtGenCowboy

    I think a step is missing or something.. I followed exactly, when I launch adb.. it shows as not being rooted.

    • NxtGenCowboy,

      Did you do the How To Root the Evo 4G (Unrevoked Method) procedure first?

      • Anonymous

        hey is there any way i can get help from you over the phone or email please let me know cause my Evo4G is tock on a black screen with a red triangle and a “!” and not even removing the battery will go back to normal. thanks in advance

        maromas_381@hotmail.com

      • Anonymous

        hey is there any way i can get help from you over the phone or email please let me know cause my Evo4G is tock on a black screen with a red triangle and a “!” and not even removing the battery will go back to normal. thanks in advance

        maromas_381@hotmail.com

  • Flanny

    When I download the recovery.img file the name just stays recovery, but in the tutorial it says recovery2.img . Also, it shows up as a zip file. Since its named differently when I am type command prompt “/data/flash_image recovery
    /sdcard/recovery2.img” it says not found. Everything worked flawless until this point.

    • Flanny

      nevermind, tried a few more times and it worked. Thanks for all the great tutoials, they are very helpful

      • Matthew

        what did you do? i need help on that exact part.

  • James

    I followed your guide on how to root and it worked very well. I followed this tutorial and it also seemed to work,but when my phone rebooted, I believe that I lost root. I dont have superuser permissions any more. Any suggestions?

    • James,

      Yes. Go flash a custom ROM in the next procedure to get superuser back (you unlock nand to be able to flash a ROM and most ROMs have superuser built in.

  • Ryan

    Okay, I’m at the first set of command prompts. Everything up until now worked fine, but every time I get to the line that says

    cat/sdcard/flash_image….

    It won’t work. Are there spaces in the command? I’m not sure what I’m missing here.

    • Matthew

      yes, there are spaces in the commands. Well i put em in anyways.

      • i can’t get the first part of the command to work. since i have evo. 2.2 and used the unrevoked procoess do i still have to do the cmd stuff??? would like to have help quickly plz.

  • Matthew

    Figured it out! when it says in the text to put the flash_recovery and mtd-eng.img files unzipped i thought it was the whole folder not the file. Gotcha! watching the videos helps a lot. haha. and if this didnt work on the newest update i just found the old update and did it off of that. Thought that was the original problem. oh well. either way its working. ๐Ÿ™‚

  • dallas schill

    When i open CMD and i type everything in after i type su it says Permission denied what should i do?

    • Dallas,

      Redo the how to root unrevoked procedure.

  • Patrick

    Thanks for the tutorial. Everything going great right up until the command line /data/flash_image recovery /sdcard/recovery2.img, I get a series of error messages that indicate a write problem, an erase problem and then says there is not enough room on the device. i checked the sdcard and there is plenty of room. Due to this error, I don;t have a recovery image to boot into. Any thoughts?

    • Alwayz Strapped

      Did you find out the problem? I have the same issue.

      Please help

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  • mike

    So i do this root and it works great and everything, then i get a message on my phone… time to update to 2.2, which i was excited for. i got to OTA update, which should take 15-49 minutes so idc. i do the update and a quarter the way through i get an exclamation point and a frozen screen, what should i do to get my phone updated?????

  • mike

    okay scratch that….. I’ve done my research and I realize I cannot do a update via the air with my phone being “unrEVOked” rooted… I want 2.2 for the updated features, “better” Wi-Fi signal, and possibly battery life.
    now I’m considering either downloading a 2.2 Froyo ROM (which i have no idea how to install even if its considered “easy”) or I’m going back to factory stock, getting froyo OTA then re-rooting the phone (can you even do that?)….

    whats you opinion on what i should do?

  • I’m on Step 14 (I think everything worked fine up til now). I did not have a “Wipe Data” option only “Wipe”. When I select it my options are
    – Return
    – Wipe data/factory reset <- This seems closest to what step 14 says to do, but also seem like I will reset everything I've done this far
    – Wipe cache
    – Wipe Dalvik-cache
    – Wipe SD:ext partition
    – Wipe battery stats
    – Wipe rotate settings

    I'm not sure what to do/select? any suggestions

    • Ryan,

      Wipe then Wipe Data/Factory Reset. That will erase all the user data on the phone which we need it to do (your contacts etc will come back once you sync with Google).

  • kevin

    when trying to enter “cat /sdcard/flash_image > /data/flash_image”
    it says invalid length?

  • Ali

    Dude thank you soo much for this tutorial !

    You have no idea how happy i am right now.

  • Shawn

    Worked perfectly! Not a single issue. Good work Unlockr and thanks for the easy to understand guide.

  • GSRacer

    My 4g stopped working after using unrevoked3 to root my phone and unlocking nand. What can I do to fix it?

  • jay

    to everyone having problems at the cmd prompt, i don’t know why he told you to unmount your sdcard before running the commands but you absolutely do not unmount it. u disconnect from using ur usb connection as a flash drive and make sure debugging is enabled and make SURE your sdcard IS mounted. sometimes adb doesn’t like a bunch of stuff on the sdcard, i had to backup my stuff to my laptop, format my sdcard in all fat32 (got rid of the apps2sd ext3 partition) then put the downloaded files onto the card just as explained. worked like a charm. ๐Ÿ˜‰

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  • anothermike

    I have the same problem as mathew. it says when i do the hboot and wait for the pc36img to update it fails and says โ€œMain version is older!, Update Fail!โ€ and then asks if i wanna do a reboot or not. Anyone else got this? Anyone else can help?

  • Uriel

    I have followed the steps as provided but im stuck on step 11 (11. When it asks you if you want to reboot select yes.) My phone doesnt reboot, it keeps boot looping into recovery.

    • Uriel

      Forget it, i started over from step 8 and it updated everything once again and rebooted. Thanks for the tutorial.

  • scott

    Hey I am able to get to #14, but when I reboot I get a red triangle -excalmation- icon… I have a sprint evo 4G froyo 2.2 and recently got an update from sprint..

    I revoked3 no problems..

    Please help :*(

  • scott

    weird, I did it like 2-3 times, and it finally wokred ๐Ÿ˜‰ THANKS!

    • Pspunbricker

      hey scott i have the same problem but mine says update failure

  • Montyq72

    Once your rooted is it then alright to re-install htc sync and use it?

    Newbie

  • Montyq72

    Once your rooted is it then alright to re-install htc sync and use it?

    Newbie

    • Yes.

      • rafael

        THE unlocker man i need help bro your the best my phone is stuck at the bootloader screen i did everything radio update v2 fail bootloader fail HELP

  • CRYSSX

    error opening /sdcard/recovery2.img: No such file or directory ……HELLP

  • pilxes

    Hello David,

    I came all the way to #10 but along the way the Radio_V2 says Fail FU /then Bootloader- Fail IC

    Now the Phone Restarts but still hasn’t loaded it’s stuck on the hTc EVO 4G Logo

    pls. help thanks.

    • olie

      im having the same problem. im stuck on the white htc evo 4g screen. wont boot past. plz help

      • Bianka Giselle

        did you ever get your evo to rcover? i need help!

    • Cubanboy4life25

      bro im having the same promblem how do we get the phone to work man im so lost

    • Bianka Giselle

      did you get this to work? i am having the same problem as you and i can’t get any support… plz help! my email is bianka.giselle@yahoo.com

  • Same problem as the other fail on Radio and on bootloader stuff on htc evo 4g screen. can we get some help please

  • anyone with the same error with the fails get the RUU and you can go back to stock and save yourself

  • Help my phone bypassed bootloader radio_v2 fail pu TP was also bypassed

  • Marydei

    My phone don’t automatically find the PC36IMG file Any recomendation?

  • Muelgrub2003

    Does this mean that if I rooted the EVO 4G gingerbread with the new rooting method that just came out a short time ago for Gingerbread, that I don’t have to do this step?

  • 3rvin

    great instructions. How about the the tablet, is it the same procedures?

    thanks