[Desire Q&A, Help & Troubleshooting] Fractalogic:
How to get back to stock HBOOT image

It worked! Thanks jmcclue! The commands are all the same as for flashing any HBOOT image.

Just for reference, this is how to do it.

Go to AlphaRev website and download the file "bravo_downgrade.img".

Set the phone to fastboot mode.

Connect it to the computer with a USB cable.

Open a command prompt (preferably with elevated privileges).

Navigate to the folder where you saved the "bravo_downgrade.img" file.

Send this command to flash it.

fastboot flash hboot bravo_downgrade.img

Send this command to reboot.

fastboot reboot-bootloader

Send this command to erase cache.

fastboot erase cache

Disconnect the phone from computer.

Select "REBOOT" from the Fastboot menu. Either that, or take out the battery and put it back in.

Boot/start up the phone normally. If you previously took out the battery, put it back in and press the power button.

Connect it to the computer. If it asks you what kind of connection, choose Charge only.

Run the RUU (ROM Utility Update) that includes the HBOOT image. If it includes the HBOOT image the file size should be around 160 MB.

Follow the on-screen instructions to complete the operation.

When done, the phone should reboot and you should have the stock HBOOT image and the stock software version.

Note! Don't remove the cable when you are sending commands to the phone. Only remove it when all commands and operations are performed.

Requirements:

RUU file for your phone.

Android SDK installed.

Java SDK installed.

HTC Sync

(ADB driver for your phone)

I am assuming you already have the SDKs all installed and set up. If not, you will have to do that first.

You will probably also need the HTC Sync installed on the computer. I think this is required for RUU to work properly. I was only receiving ERROR 170 when running the RUU ("phone not connected" or "not found" or whatever), until I installed HTC Sync. You will find it on HTC website or you can find the old version on your original 2 GB microSD card you got with the phone. I personally prefer the old version because the new HTC Sync feels like bloatware and is resource-hungry for no apparent reason (just some flashy graphics).

You may or you may not need the ADB (Android Debug? Bridge) driver for your phone. I have mine, downloaded from XDA Developers forum years ago. It's said that installing HTC Sync will include the proper drivers for ADB and solve the issue with missing driver for "Android 1.0". I didn't find this to be true. I tried different, supposedly HTC drivers only packages, from different web sources, and none of them worked. Except for the one I found on XDA Developers forum. I'm not 100% sure but I think this driver is only needed when the phone is in recovery mode. But it doesn't hurt to install it just as a precaution or at least have it prepared and ready to install.

To get RUU files:

You can either go to the HTC Developer website and try to locate the files there, or you can visit a website like Shipped-ROMs and try locating a "Bravo" or "Desire". Bravo is the codename for Desire. Then you probably want to download the ones that have "WWE" (World Wide English) in the names. These are based on English but have translations to other languages as well. And you want the ones where it says "HTC" in the name, if your phone is not carrier specific and not re-branded. Mine is not.

This is the name of the RUU file I used:

RUU_Bravo_Froyo_HTC_WWE_2.10.405.2_R_Radio_32.44.00.32U_5.09.05.30_2_release_142828_signed.exe

This gave me Android 2.2 which is what I had on my phone when it was new.

Check:

To verify that you have the proper HBOOT version and that you have S-ON you can show the HBOOT menu (volume down + power button). Here is what it should look like.

AFTER flashing with RUU;

BRAVO PVT3 SHIP S-ON

HBOOT-0.93.0001

MICROP-051d

TOUCH PANEL-SYNT0101

RADIO-5.09.05.30_2

Aug 10 2010,17:52:18

BEFORE flashing with RUU;

AlphaRev Unlock

BRAVO PVT3 SHIP S-OFF

HBOOT-6.93.9999

MICROP-051d

TOUCH PANEL-SYNT0101

RADIO-5.09.05.30_2

Aug 10 2010,17:52:18

BEFORE flashing the HBOOT with bravo_downgrade.img;

--- AlphaRev ---

BRAVO PVT3 SHIP S-OFF

HBOOT-6.93.1002

MICROP-051d

TOUCH PANEL-SYNT0101

RADIO-5.09.05.30_2

Aug 10 2010,17:52:18