[Desire 820 General] h1dd3n_sn1p3r:
- Your warranty Might be Void
- I am not responsible for any kind of brick's
- This was tested on A51_DTUL try others on your own risk
- Also Works for boot loop : WIPED SYSTEM : SOFTWARE PROBLEM : OTHERS TRY YOURSELF
- You May PM me problem related to this thread & we can get Linked in whatsapp/Viber for instant support

~~~ :) MAGIC OF RUU [Upgrade to lollipop][Re-lock/Re-Unlock BOOTLODDER]~~~

This Post is dedicated to those peoples who don’t have Software update option inside Setting>about>

:: ALSO WORKS FOR PHONES STUCK AT BOOT LOGO/LOOP : WIPED SYSTEM : SOFTWARE PROBLEM : OTHERS TRY YOURSELF ::

---- If some experts knows better way than feel free to post at comment ----

TESTED MODEL: HTC desire 820U [ A51_DTUL & IMEI was registered from China ]

I myself was suffered from this problem since some weeks on my new Smartphone HTC desire 820U.

I was sick of trying to flash Custom ROMs ,OTA, restore TWRP backup of lollipop but all throw some different errors.

After a Many days Test I came back to the result which is as follows & test was made on my rooted HTC desire 820U

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READ THIS FOR PRODCT VER,CID & MID INFO

-Before you download or install firmware

- Check bootlodder & look for Product Ver Region like eg: "A51_DTUL" | eg: "A51_UL" etc

- Look for you CID

- Look for you MID like eg:"0PFJIMG" | Your's could be "ABCDEF" or what ever | While renaming & hitting command follow you own name respectively

- If your device is S-ON then both modelid and cidnum must match

- MODELID = eg. 0PFJIMG & CID =eg. 1111111111 [ check urs ]

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Requirements:

1. HTC desire 820U with A51_DTUL <check this in Bootloder see attachment> | YOU MAY HAVE DIFFERENT RADIO & SPECIFICATION SO BE SURE TO GET YOUR'S PHONE RUU

2. RUU files for KITKAT 4.4.4 [Link https://mega.nz/#!CEtXFa6B!pfI1rxoQQr79Q9YMr3KA6yms6klsfyMjrO35qSOq4Mg ] | CHECK YOUR

3. PC

4. Fastboot Drivers [LINK https://mega.nz/#!9gZEHbhD!nG8RljG3FbnKoXzrRtBs8rhtGiDUz1s0b7l_lnxkW4U ]

5. Bootloder to be RE-Locked [Need to re-lock it if it was UNLOCKED for ROOTING]

6. 30% plus battery

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CAUTION:

----- This will wipe your entire System so make all types of backup, if you are not aware of backup then look for TWRP backup or CWM backup or use TITANIUM TOOL for backing up your apps and data ----

Installation Step-1

1.	Boot your phone to Bootloder [ Turn off phone , Hold power & vol down ]

2.	[ON PC ]extract fastboot drivers install ADB and fastboot.exe

3.	HOLDING shift open CMD to open CMD on that location

4.	Enter command [fastboot reboot-bootloader ]

5.	Command [fastboot oem lock ]

6.	Now your bootloder get RE-LOCKED

Installation Step-2

1.	Download the KIT KAT Official Indian region RUU from the above Link

2.	Rename the downloaded ZIP to “0PFJIMG.zip” [ Re-name as per you MID eg: O6FSLDSN ]

3.	Copy the 0PFJIMG.zip file to the External SD card

4.	PUT you SD card to phone and press fastboot from HBOOT

5.	HBOOT will detect your 0PFJIMG.zip file automatically

6.	You will be asked to press Vol up for update

7.	Just press once VOL UP for update process it will take some time wait until you will be prompt to press Power once to reboot system.

8.	Finally as your system gets restart you will be greeted with New OS like same when you had buy it.

9.	That’s the welcome of KIT KAT

10.	Go & check SETTINGS>ABOUT> you will find software update option

11.	That’s It Done. :good::good:

Installation Step-1

1. Place the Downloaded RUU in the fastboot folder

2. Re-name it to "firmware.zip"

3. Boot the phone into Bootlodder [VOL DOWN + POWER]

4. Command

fastboot reboot-bootloader

5. Command

fastboot oem lock

If bootlodder is not Locked till now

6. Command

fastboot oem rebootRUU

7. HTC silver Logo will apper in a while

8. After you see silver logo

9. Command

fastboot flash zip firmware.zip

10. Progress bar will be display,wait until it gets done completely

11. Command

fastboot reboot

12. Done reboot the system :good: