[GUIDE] Downgrade ROM and Radio from OTA to Stock

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This guide will show you how to downgrade your MyTouch 4G from the recently released OTA to the stock build.

This WILL wipe your device! I am not responsible for any damages!
NOTICE: A lot of people have reported -including me- that using this method to downgrade your firmware will cause your MT4G to not receive the OTA that was released right after the phone was.

What You Need:

• Hex Editor such as Bliss
• Temp-rooted MyTouch 4G
• ADB
• This ROM - Stock ROM

1. Download the ROM and rename to PD15IMG.zip
2. Place PD15IMG.zip on the root of your SD card
3. Un-mount SD Card
4. adb shell
5. su
6. Now, run this command:

dd if=/dev/block/mmcblk0p17 of=/sdcard/misc.img

7. Mount your SD card
8. Copy misc.img from your SD card to your computer
9. Now open the misc.img on your computer in your Hex Editor
10. You should see something like:

1.17.531.2

11. Change that to:

1.14.531.1

12. Now save as miscnew.img
13. Unmount your SD Card now
14. Now in adb shell run this command:

dd if=/sdcard/miscnew.img of=/dev/block/mmcblk0p17

15. Power off your device
16. Now boot into Hboot by holding down "volume down + power"
17. The phone will scan for PD15IMG.zip and will ask you to flash it
18. Select Yes [DUH!]

You should now be downgraded from the 2.2.1 OTA back to stock 2.2!

I would like to note that this downgrades the HBoot/Bootloader, radio, system, data, amongst other partitions of your phone.
Also, since I downgraded, I have not received any notifications for the OTA as of 11/8/10.

This guide is a derivative of Apache14's OTA and Radio downgrade guide for the T-Mobile G2: Here

Cool

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What are the advantages of downgrading?

Originally Posted by cdw9800

What are the advantages of downgrading?

At the moment, probably nothing.

If an exploit for root were ever found in the original stock build, but was patched in the OTA, then this would be useful.

I am getting..

cannot open for write: Read-only file system

That is after following everything to the letter....

Originally Posted by travisjames

This guide will show you how to downgrade your MyTouch 4G from the recently released OTA to the stock build.

This WILL wipe your device! I am not responsible for any damages!

What You Need:

• Hex Editor such as Bliss
• Temp-rooted MyTouch 4G
• ADB
• This ROM - Stock ROM

1. Download the ROM and rename to PD15IMG.zip
2. Place PD15IMG.zip on the root of your SD card
3. Un-mount SD Card
4. adb shell
5. su
6. Now, run this command:

dd if=/dev/block/mmcblk0p17 of=/sdcard/misc.img

7. Mount your SD card
8. Copy misc.img from your SD card to your computer
9. Now open the misc.img on your computer in your Hex Editor
10. You should see something like:

1.17.531.2

11. Change that to:

1.14.531.1

12. Now save as miscnew.img
13. Unmount your SD Card now
14. Now in adb shell run this command:

dd if=/sdcard/miscnew.img of=/dev/block/mmcblk0p17

15. Power off your device
16. Now boot into Hboot by holding down "volume down + power"
17. The phone will scan for PD15IMG.zip and will ask you to flash it
18. Select Yes [DUH!]

You should now be downgraded from the 2.2.1 OTA back to stock 2.2!

This guide is a derivative of Apache14's OTA and Radio downgrade guide for the T-Mobile G2: Here

NM, sdcard has to be mounted....

Originally Posted by Mr Bill Florida

NM, sdcard has to be mounted....

At which part does the sdcard have to be mounted?

During this part?:

dd if=/dev/block/mmcblk0p17 of=/sdcard/misc.img

I guess that would make sense, but I didn't have to have my SD Card mounted during this part which makes me wonder.

Originally Posted by travisjames

At which part does the sdcard have to be mounted?

During this part?:

dd if=/dev/block/mmcblk0p17 of=/sdcard/misc.img

I guess that would make sense, but I didn't have to have my SD Card mounted during this part which makes me wonder.

Originally Posted by travisjames

1. Download the ROM and rename to PD15IMG.zip
2. Place PD15IMG.zip on the root of your SD card
3. Un-mount SD Card
4. adb shell
5. su
etc......

step 3 ignore

Originally Posted by travisjames

12. Now save as miscnew.img
13. Unmount your SD Card now
14. Now in adb shell run this command:
etc......

step 13 ignore

Originally Posted by travisjames

I would like to note that this downgrades the HBoot/Bootloader, radio, system, data, amongst other partitions of your phone.
Also, since I downgraded, I have not received any notifications for the OTA as of 11/8/10.

When I received my update to 2.2.1 it was over 5 hours after I activated the phone. Might take as long or longer depending on the network.

Originally Posted by travisjames

This guide will show you how to downgrade your MyTouch 4G from the recently released OTA to the stock build.

This WILL wipe your device! I am not responsible for any damages!

What You Need:

• Hex Editor such as Bliss
• Temp-rooted MyTouch 4G
• ADB
• This ROM - Stock ROM

1. Download the ROM and rename to PD15IMG.zip
2. Place PD15IMG.zip on the root of your SD card
3. Un-mount SD Card
4. adb shell
5. su
6. Now, run this command:

dd if=/dev/block/mmcblk0p17 of=/sdcard/misc.img

7. Mount your SD card
8. Copy misc.img from your SD card to your computer
9. Now open the misc.img on your computer in your Hex Editor
10. You should see something like:

1.17.531.2

11. Change that to:

1.14.531.1

12. Now save as miscnew.img
13. Unmount your SD Card now
14. Now in adb shell run this command:

dd if=/sdcard/miscnew.img of=/dev/block/mmcblk0p17

15. Power off your device
16. Now boot into Hboot by holding down "volume down + power"
17. The phone will scan for PD15IMG.zip and will ask you to flash it
18. Select Yes [DUH!]

You should now be downgraded from the 2.2.1 OTA back to stock 2.2!

I would like to note that this downgrades the HBoot/Bootloader, radio, system, data, amongst other partitions of your phone.
Also, since I downgraded, I have not received any notifications for the OTA as of 11/8/10.

This guide is a derivative of Apache14's OTA and Radio downgrade guide for the T-Mobile G2: Here

Nice work!

Originally Posted by cdw9800

What are the advantages of downgrading?

This will probably be the first step to rooting when the devs finally figure it out. :thumbup:

Oh ok I figured that good with ill keep it in mind

Originally Posted by travisjames

At the moment, probably nothing.

If an exploit for root were ever found in the original stock build, but was patched in the OTA, then this would be useful.

Sent from my HTC Glacier using XDA App