This thread is intended mainly for people who have phones with SLCD displays. Please take a minute to read it before attempting to run any updates, downgrades, or applying any RUUs.
There have been lots of posts and confusion about HBOOT 0.83, 0.92 and SLCD over the last few weeks. These newer versions of the bootloader are installed by certain official updates, and come pre-installed on most new phones. To get straight to the point: HBOOT 0.83 is not a problem. Quite a few people have ended up breaking their displays by trying to downgrade, when it isn't necessary.
Q. I applied an RUU/downgraded to HBOOT 0.80 and now my screen doesn't work.
A. You can recover by upgrading to stock froyo. Just insert your goldcard and run this generic RUU: http://shipped-roms.com/shipped/Brav...022_signed.exe
Q. Which RUUs are safe to use with an SLCD screen?
A. All froyo RUUs are safe (release beginning 2.x). Otherwise do not attempt to use any other RUU that isn't listed in this post.
Q. How do I upgrade to stock unbranded froyo (without root)?
A. Use the RUU for froyo in question 1.
Q. I have upgraded to froyo, but want to downgrade/root.
A. Don't try using old methods as they will break SLCD screens. You can use a tool I have developed. Read the thread here: http://forum.xda-developers.com/showthread.php?t=768256
Q. How do I know if my screen is SLCD or AMOLED?
A. A black background in low light, at certain angles, will have a slight grey sheen to it if your screen is SLCD. On an AMOLED screen it will remain the same black. If you got your phone before July 2010 it is AMOLED.
Q. Does HBOOT 0.83 mean I have an SLCD screen?
Q. Can I root my phone on HBOOT 0.83 and use custom recovery?
A. Yes! Use unrevoked3. http://unrevoked.com/recovery/
Q. My screen goes blank when I use custom recovery with unrevoked3.
A. You are using an old version of unrevoked3. Please try again with the latest version.
Q. Can I use AmonRA custom recovery instead?
A. Yes, it has now been updated to support SLCD. Install via unrevoked3 with this image: http://amonra-mod.googlecode.com/fil...7.0.1-R5.1.img
Q. What is the difference between HBOOT 0.83 and 0.92?
A. 0.92 is installed currently only if you apply the official froyo update or if you buy an unbranded phone with froyo. You cannot directly root running froyo yet, but this will soon be available. In the meantime you must downgrade to Android 2.1.
Q. How do I downgrade to HBOOT 0.80 from 0.83?
A. Don't - there is absolutely no reason to. If you want to root or use a custom ROM or debrand you should not try to downgrade.
Q. Can I debrand my phone with HBOOT 0.83?
A. Yes. What's important is your software release, not your bootloader version. If your software version is 1.21.405.2 or lower (for example, branded O2 phones), you can simply use this generic RUU with a goldcard to debrand and install stock 1.21.405.2. You can then root or upgrade to froyo if you wish to. This RUU will also flash your HBOOT to 0.83. http://shipped-roms.com/shipped/Brav...222_signed.exe
Q. My software version is higher than 1.21.405.2 (e.g. I applied the Vodafone branding update). Can I debrand?
A. If you want Android 2.1 you need to use the downgrade tool. If you want froyo, just apply the froyo RUU as described in the first question.
Q. I have an SLCD screen. Can I run custom ROMs?
A. The latest ones will work. The pre-rooted version of official froyo works fine including all custom ROMs based on it (kernel 22.214.171.124).
Q. Can I rebrand my rooted/debranded SLCD phone?
A. You will need a branded froyo RUU. Currently available: O2 126.96.36.199