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 our How To Load a Custom ROM on the HTC Evo 4G procedure.
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
…
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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!
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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.
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can’t get passed the first set of cmd prompts. help.
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I think a step is missing or something.. I followed exactly, when I launch adb.. it shows as not being rooted.
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NxtGenCowboy,
Did you do the How To Root the Evo 4G (Unrevoked Method) procedure first?
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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.
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nevermind, tried a few more times and it worked. Thanks for all the great tutoials, they are very helpful
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what did you do? i need help on that exact part.
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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?
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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.
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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.
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yes, there are spaces in the commands. Well i put em in anyways.
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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.
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When i open CMD and i type everything in after i type su it says Permission denied what should i do?
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Dallas,
Redo the how to root unrevoked procedure.
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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?
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Did you find out the problem? I have the same issue.
Please help
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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?????
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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?
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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
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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).
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when trying to enter “cat /sdcard/flash_image > /data/flash_image”
it says invalid length?
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Dude thank you soo much for this tutorial !
You have no idea how happy i am right now.
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Worked perfectly! Not a single issue. Good work Unlockr and thanks for the easy to understand guide.
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My 4g stopped working after using unrevoked3 to root my phone and unlocking nand. What can I do to fix it?
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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.
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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 “Main version is older!, Update Fail!” and then asks if i wanna do a reboot or not. Anyone else got this? Anyone else can help?
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