[Legend Android Development] LSM1:
I had partial bricking problem with boot cycling and a lack of standard usb connectivity. Here is an overview of how I solved this problem.

Background

I rooted my unlocked Bell Canada Legend using the three guides by David Cogen at the unLocker: Downgrade the HTC Legend to 1.31 so It can be Rooted (12.13.10); How to Root the HTC Legend (Updated 12.13.10), and How to Load a Custom Rom on the Legend.

This involved, among other things, making a gold card, installing the Windows Android SDK, downloading the specified downgrading tool, flashing RRU_LEGEND_HTC_WWE_1.31.405.5 ... signed.exe, installing HTC Sync 2.0.33, getting Legend rooting tools, and Loading the excellent Keep it Simple rooted 2.1 ROM (This was before the KIS 2.2 Rom had been released). With some minor difficulties I got this going and the KIS rooted rom was excellent.

However, my real intention had been to install a rooted version of Android 2.2. However, it would not install as the HBOOT version was 0.30.

I tried using the "Howto Update HBOOT to 1.00 keeping your Legend rooted" but I deviated from the instructions and ended up with a semi-bricked Legend that exhibited the commonly encountered boot cycling problem.

After about 8 hours of deep anxiety if found a solution. I lost root capability but got an unbricked, functioning phone with the latest Android 2.2. Here's an overview that may be useful to some Android newbies like me.

PROBLEMS

Boot cycling: start booting process with a buzz, green HTC logo on a white screen for a while, then black screen and reboot, on so on. No access to a functioning system.

No usb connection with Android SDK. i.e.: command adb device showed on available device, HTC* offline.

At this point I though I had a brick. There are some solutions to this problem posted but they appeared way too complicated.

Fortunately, the fastboot menu (hold down return button while pressing power on switch) came up as did the hboot menu. However, I couldn't get to recovery in the hboot menu.

Solution.

On Windows PC used for this work I installed the unRevolkedmod USB drivers which allowed me to connect with the Legend connected via usb cable and in fastboot mode.

In a MSDOS command window in Windows XP I executed from the AndroidSDK subdirectory containing the fastboot executable (in my case C:\...android-sdk-windows\tools\) "fastboot oem enableqxdm 0" which enabled fastboot usb-plugin on the phone (see it com up in red text in the fastboot menu).

In another MSDOS command window I changed to the unzipped "r4-legend-root" directory and ran "fastboot-windows.exe oem rebootRUU" that allowed me to execute the latest RUU (either execute the RUU from this MSDOS command window or click on the file in Windows File Manager) and install the stock HTC 2.2 rom normally following the RUU menus. I used the available RUU_Legend_Froyo_S_HTC_WWE_3.15.405.3.....160328_signed.exe.

I now have a fully functional Legend with the stock unrooted HTC Android 2.2 with hboot 1.01.

Also, I tried the "Rooting with HBOOT 1.0" howto following the directions exactly, but couldn't get to work. I got as far as a functioning Android 2.1 but didn't/couldn't get the 2.2 rom to install as 2.1 wasn't rooted. I think I'll wait until the knowledge base improves. I just reinstalled the stock HTC 2.2 and it is running fine. Much better than a brick!

Although this is short on details, they are available in various threads. I trust that this may be of some help to others that are in the situation I was in. The answer is out there, it just takes a lot of digging!