[Droid Eris Q&A, Help & Troubleshooting] bftb0:
Take your time, and read and understand this whole post before you begin.

[size=+2]Files Needed:[/size]

Collect all the files you will need, get them on to the root folder of your SD card, and verify their MD5 signatures (the copy that makes it to your SD card, not the copy on your computer) :

"rom.zip" - the 1.51.0000 bootloader install payload - here **

MD5: daab6bcbe78c41938a95c4963c5c44e8

custom recovery - either Amon_RA's ("recovery-RA-eris-v1.6.2.img"), or scary alien's trackball-free derivatives here (e.g. the New 1.7.1 version)

"ErisMiscReset_v0.9.zip" here

"MTD_Inspect_v0.9.zip" here

"ErisMTDNuke_v0.9.zip" here (also, please see disclaimer here)

"Eris_RootROM_v2.19.605.1_PB00IMG.zip" from shipped-roms.com. Note that this (also) is renamed to PB00IMG.zip at the appropriate time. **

A custom (dev) ROM, or even a fully stock ROM such as the HTC Eris March 2011 OTA Stock ROM - v2.41.605.6

[size=+2]Installation Method:[/size]

Note:

A less thorough method than what is described here, but shorter, is reported here. Even though I built the "ErisMTDNuke_v0.9.zip" repair tool, I do not advocate using it unless it is confirmed to be absolutely necessary. Moreover, in almost every case, having the Eris S-OFF bootloader on a rooted phone is an advantage, and (also) having the "misc" partition "MainVer" value reset back to a low value after fooling with RUUs or PB00IMG.zip installs is a good idea to prevent future disasters. The short method does not document either of these two steps.

Note #2: In any of these procedures, it is important to do so with A FULLY CHARGED PHONE. Do not let the phone sit idle for long periods of time in HBOOT, FASTBOOT, or RUU modes - even with the Eris plugged in to a USB port, in those modes it will discharge very rapidly - about two hours or so. That little green light is your friend.

- get fastboot on a PC working and communicating with the phone in its' current state (with the phone in fastboot mode or RUU mode). Doubtful if I will reply to inquiries about Windows and driver installs - it's covered in gory detail all over the place. Same goes with getting a copy of "fastboot.exe" for windows. (Google is your friend).

- Install the "rom.zip" file for the 1.51.0000 bootloader, (Rename to PB00IMG.zip and install it by booting the phone into HBOOT mode**)

- register with htcdev.com for unlocking this new Eris bootloader & follow the bootloader unlocking instructions (you can skip downloading & running the RUU, as you have installed the bootloader already)

- create a zip file with a custom recovery image in it (named "recovery.img"), and an "android-info.txt" file with MainVer set to 2.42.0000 (see step #3 of this XDA post).

- using fastboot and the phone in RUU mode, flash this zip file ("fastboot flash zip zipfilename.zip") Again, see step #3 of the link above.

- power off the phone and boot into the custom recovery and flash the ErisMiscReset_v0.9.zip file (watch for any errors - stop if you see errors!).

- in the same recovery session flash the MTD_Inspect_v0.9.zip file and determine if you have massive (bad block) corruption in any of /boot, /system, or /data. (See instructions here)

- If the above mentioned partitions only have one or two bad blocks, skip the next step.

- Flash (in recovery) ErisMTDNuke_v0.9.zip

- Re-lock the 1.51.0000 bootloader (phone in fastboot mode) with "fastboot oem lock"

- Flash the Eris Root ROM (from shipped-roms.com), using the HBOOT+PB00IMG.zip install method. The objective of this step is primarily to get rid of the 1.51.0000 bootloader, and install the 1.49.2000 S-OFF bootloader. Note this will stomp on your custom recovery (unless you use the battery pull trick), but that's OK.**

- get the custom recovery back onto the phone - using either the standard Eris rooting tools (Dummies or One-Click), or simply flash it using fastboot (e.g. "fastboot flash recovery recovery-RA-eris-v1.6.2.img")

- one last time: in the custom recovery, flash the ErisMiscReset_v0.9.zip file

- Install a ROM and be happy.

** after using any PB00IMG.zip file, it is a really good idea to rename it ASAP, so that you don't accidentally re-install it by inadvertently powering up the phone in HBOOT mode.

bftb0