[Redmi 9 / Poco M2 Guides, News, & Discussion] Shas45558:
Remember.....

Sp flash tool work (without authorization) with v11.0.4.0-v11.0.8.0......but v11.0.4.0 is best for sp flash tool work without authorized account...

This Post is very important for all redmi 9 users, who Want to modify his or her device At Home Without Going To xaiomi customer center and Pay somebody to fix His Or Her device.

Theory:

Our redmi 9 is MediaTek bAse Device. That's Mean it is easily to break without any reason. When Break your device you cannot go fastboot mode or recovery mood.Only boot logo is coming and then it reboot every time. Then The only option is left that is you can or must be flash it with SP flash tool. The SP flash tool flash device with Brom Mood.It is same as Snapdragon EDL mode. Unlik Snapdragon You do not need to disassemble your device to go Brom Mood.The Mood is always there when you reboot your device.If you connect your device With If your PC have Vcom port driver(can be download from this post) Then the computer Can recognise Your device As Vcom Port.But you cannot use this port to flash device Xiaomi Is lock the port. But good News is global V11.0.4.0 has some bug.You can use SP flash tool to flash. An upper Version it may possible But doesn't Know When they fix This Bug And SP flash tool is unable to flash lT.So you have to stay on V11.0.4.0. if You Are in higher version When You Read The Post Do Not Worry You Can Downgrade V11.0.4.0 . test All Framware At This Time of Writting The Post ,That The AntirollBack Protection Is Not Active.That's Mean You Can Downgrade Your Framwar.

How To Unbrick Your Device?:

If You Are In V11.0.4.0 then It Work Definitely Unless You Flash Wrong Preloader.Bin Or Earse Preloader.bin .intall Vcom Driver To Your Pc(DownloaD From Post).If Your Device Can Defect As Vcom Driver Then You Good TO Go....

Follow The Below Link To Flash With Sp Flash Tool.Remember Do Not Flaah Preloader.Bin File....

https://xdaforums.com/t/redmi-9-brick-problem-solution.4155871/#post-83394363

How To UpdaTe Your Device Without UpdaTe The Framware?:

It is very good and important question. Because If you update your Device With Recovy Method With Recovery Rom Then Your Framware Is Also Update.So It Is Not Possible To Use Sp Flash Tool Then.To Avoid This Problen You Can Follow Two Method Which I Describe Below.....

1.Fastboot Rom Method(Easy):

You Have to download the fastboot version Of your ROM which You Want To Install.Then extract The Fastboot Rom And You Need super.img and boot.img File.You Also Need A vbmeta.Img(Download From This Post). Then Go to fastboot mode Of your device and Flash Via Below Cmd

fastboot flash super super.img

fastboot flash boot boot.img

fastboot flash vbmeta vbmeta.img

Erase your all user data from Going To Recovery Mood(power+Volume Down).Reboot Your Device If Get Bootloop Then Flash Magisk Patch Boot.Img From The Fastboot Rom.If you Do Not Know How To Patch Then Follow The Below Link..

https://xdaforums.com/t/root-redmi-9-without-twrp-and-data-lost.4157721/#post-83419803

In This Way You Can Flash Any Variant of FastbOot Rom.That's Mean You Can Use Chaina Rom With GlobAl Framware..

2.RecOvery Method(Hard)

Requirements:

*Recovery Rom(any Version And Any Variant)

*Pc Or Laptop With Windows And Linux(Ubuntu 20.4 is Batter)

*Some Knowledge About Ubuntu Cmd.

Linux part

Extract 4 file From The Downloaded Recovery Rom

1.system.new.dat.br

2.system.transfer.list

3.product.new.dat.br

4.product.transfer.list

And Download sdat2img.py(from This Post extract from dat2img-master.zip)

Keep This 5 file In Same Folder And Ooen A Terminal From The Same Location.run The Below Cmb In Linux Environment One By One.

brotli -d system.new.dat.br

brotli -d product.new.dat.br

./sdat2img.py system.transfer.list system.new.dat system.img

./sdat2img.py product.transfer.list product.new.dat product.img

After Run All 4 cmd Successful Then You Can Find Two File In Same Folder Which Are system.img And .product.img

Linux Part Is End Now Go To Window Os...

now Go To Your Device fastboot MooD And Connect Your Device With Pc And Run Below Cmd

fastboot reboot fastboot (For Going To Fastbootd Mood)

When You Go To Fastbootd Mood Then Open Cmd From Where Your CreateEd File Is And Run Below Cmd

fastboot flash system system.img

fastboot flash product product.Img

fastboot -w

fastboot reboot

Do Not Forget To Flash vbmeta(From This Post).flash vbmeta With fastboot Mood And When You Flash system and Product Then You Must Get A Error Like"Invalid spare At Header Magic" do Not Panic It Is Simple....

Extra:

if You Want To Use vendor.img Then you Can Also Extract vendor.img With The Above Method.and Can Flash It Via fastbootd Moid.If You Flash Vendor.img Then Do Not Forget Fo Flash boot.img From The Recovery Rom.flash boot.img with fastboot mood

If this post helpful them do not forget to thank me.Need lots time to make this post.if any questions then feel free to ask..