今天早上一時衝動太快unroot改成官方的2.2,接下來一整天都再想要怎麼讓他再rooted...
爬了好多地方的文,都不解...最後終於還是在XDA找到解決的方法了。
我的機子當初狀況:
1.刷官方ROM,使用版上提供的的1.20.751.5_Radio_32.36.00.28U_4.06.00.02_2_release_126175_signed降級失敗,原因是版本不符合。
2.對岸提供的降級方式PB99IMG.zip也失敗,原因可能是SPL鎖住了。
3.機子狀態:s-on的,HBOOT 0.92。
4.使用downgrade之後會降級到0.83,之後再使用http://www.mobile01.com/topicdetail.php?f=566&t=1657984來root機器。
5.root之後就有recovery介面了,可以下載版上的自製ROM來快樂的刷了。
基本上就是照裡面的作法去做就對了,然後成功的話會是還沒有root過的2.1系統。
給跟我一樣卡在官方2.2降不下去的人一個解決的方法,感謝XDA那位神人解救了我們

PS:不是Amoled的要看清楚一點,因為我自己是Amoled,因為有人說會壞機,但是XDA這篇文章說可以。後面有版友是SLCD回報降級成功。
-------------------------------------------原文不負責亂翻譯----------------------------------------------------
This utility currently works best with Linux, but a simple Windows script is included (image provided). Please post your results.
(重點就是Linux和WINDOWS都可以,我自己是Windows7 32位元)
Requirements:
A working goldcard if your phone is or was branded.(如果你的手機是官方的必須要有金卡)
At least 150mb free on your sdcard/goldcard.(SD上有150mb空間)
The downgrade utility(點原文的這個下載)
md5sum: d4fb6dee7de63a29d518373eafa361c3
Process:
Previous froyo downgrade options have resulted in a broken screen for SLCD phones, and will not work at all on any phone with a software version higher than stock froyo (such as branded froyo updates).反正就是SLCD有不行的案例。
This utility will quickly and easily downgrade froyo to stock Android 2.1 (HTC software version 1.21.405.2, radio 32.41.00.32U_4.08.00.09, hboot 0.83), which can then be rooted with unrevoked3. The downgraded ROM is fully compatible with SLCD screens.他提供的方式[就是上面下載的東西]完全可以支援SLCD當然AMOLED也是,可以還原到出場未經ROOT的手機狀態
If you instead want to flash a different RUU (requires Windows) you can skip the downgrade image (note: SLCD owners should be careful flashing other RUUs, it will likely break the screen). It isn't necessary to flash another RUU if you want to install a custom ROM.如果用戶不想刷他付的RUU可以自己找,但是請小心後果,尤其是SLCD。建議大家就先刷他的在刷版上的吧。
The downgrade will work on SLCD and AMOLED phones and ANY version of HBOOT.這個降級程式可以運作在SLCD和AMLED上面,以及任何版本的HBOOT
Do not attempt to use this on a CDMA Desire, since this flashes a new radio.請不要把它用在CDMA的 Desire上面,因為它是刷一個新的radio。
This appears to work on Android 2.1 too, and should also work on phones that are already rooted. The process is simple and requires minimal intervention. A few reboots take place, and this is nothing to worry about.他應該可以運行在2.1上,也應該可以運行在已經roooted的手機上,整個過程很簡單。
Linux InstallationLinux的安裝方式,我不是用這個的,看不懂,跳過
1. Download and extract the utility in a terminal:
$ unzip downgrade.zip
$ cd desire_downgrade
2. Enable USB debugging on your phone. Ensure 'ask me' is set under 'Connect to PC' setting. Plug in your phone.
3. Create the correct partition image.
$ sudo ./fixmisc.sh
4. Run the utility.
$ sudo ./downgrade.sh
4. Wait for the process to complete.
If you chose not to downgrade, you can now flash any RUU.
Windows InstallationWindwos的安裝方式
0. Install HTC Sync (driver required).安裝 HTC Sync 和驅動。
1. Extract the downloaded zip file fully (do not just click on the zip file).將他付的壓縮檔完整解壓縮在任何位置
2. Enable USB debugging on your phone. Ensure 'ask me' is set under 'Connect to PC' setting. Plug in your phone.USB除錯必須打開,並且設定連接到電腦,應該就是Sync吧,我自己Run的時候沒注意到有沒有設定連接到電腦,反正衣錠不是充電或是磁碟機模式,那就設定Sync吧。
3. Create an mtd0.img file from this website, using version 1.15.405.3, and copy it into the folder, overwriting existing file: http://ks33673.kimsufi.com/misc/
(This step may not be necessary, needs further testing)製作一個mtd0.img巴拉巴拉一大堆,後面說也許不需要,需要觀察,我自己沒有弄,它裡面自己有付我也沒改就直接刷了,因為我找不到我的CID...HTC__XX這個我找不到,所以無視。
4. Double click on the win-down file.上面都完畢之後,請雙擊壓縮檔中的win-down[已經官方ROM的我是放入金卡在手機上才執行這個動作的]。
5. Follow instructions and wait.按照說明去做吧,記得看螢幕上的字,基本上都是按任何一鍵繼續,只有到最後須要看一下,好像是按手機上的音量鍵+決定刷他的ROM,按電腦鍵盤任一鍵取消,我有點忘了,不是很難的英文,需要的朋友自己稍微留意一下。
Notes
This process will wipe all the data from your phone (except the sdcard).整個過程會完完全全消除所有在手機上的資料
The downgrade will not work on branded phones unless a goldcard is inserted.整個降級的過程中,如果你的手機是官方ROM的話,在缺乏金卡的情況下是不會成功的。
The process will flash your recovery partition back to stock.整個過程會把你的手機變成出場的樣子
The downgrade installs an official (unbranded and unrooted) stock HTC ROM.沒什麼,反正就會把你的手機變成沒有root的樣子
The downgrade does not depend on any version of HBOOT.這句話應該是不受任何HBOOT的影響都可以降級
SLCD only: if you wish to root the phone after downgrading you must use an updated recovery image with unrevoked3.如果你是SLCD的而且妳想要在降級之後root手機的話你必須要使用unrevoked3...大致啦。
Testing Status
Appears to work well: Downgrade on branded SLCD Desire successful from stock froyo in both Linux and Windows.結論是說他測試SLCD是降級成功的,無論是哪個作業系統