[T-Mobile HTC One (M8)] TheKookieGuy:
~Disclaimer~

If You Brick Or Damage Your Device I Take No Fault

Do This At Your Own Risk

Read Steps Carefully

~Disclaimer~

This Will Wipe Your Device Completely And Return It To STOCK (How It Was When You Got It Out From Box)

~Device Specifications~

Phone Model: HTC One M8 (T-Mobile)

Bootloader: LOCKED Or RELOCKED

CID: T-MOB010

Android: 6.0 (Marshmallow)

Root Status: Doesn't Matter

~Device Specifications~

~Prerequisites~

Download: RUU_M8_UL_M60_SENSE70_MR_TMOUS_6.20.531.5

Name Of File

You Can Get This On http://www.htc.com/us/support/htc-one-m8/news/

(Not Posting Link, Just Copy And Paste Into Your Browser)

Phone Battery At 30%+ If You Get Error 120 Even If Your Battery Is Above 30% Enter Recovery And Go Into Fastboot

ADB/Fastboot

Latest HTC Drivers Installed

Windows Computer To Run The RUU.exe

~Prerequisites~

~Steps~

Step 1: Make Sure You Have Developers Options Enabled

Go To Settings​

Scroll Down To About And Click On It​

Depending On Your Custom ROM That You're Running Find Build Number And Tap At Least 7 Times​

If You're Running Stock And Want To Upgrade Just Tap About, Then Tap Software Information, Then Progress To Click More, Then Tap Your Build Number 7 Times​

Step 2: Go Into Developers Options And Enable USB Debugging

Go To Settings​

Scroll Down To Developers Options And Click On It​

Scroll Down A Little Bit And Tap/Check USB Debugging​

Do This Only If Your Bootloader Is UNLOCKED, If Yours Is Already Locked Scroll Down To Step 3B

Step 3A: Boot Your HTC One M8 Into Bootloader Or Recovery Steps Below

Power Your Device Down Completely​

Click And Hold The Volume Down Button​

While Holding The Volume Down Button Use Your Other Hand And Hold In Power Button At The Same Time And Continue To Hold​

After About 5 Seconds Let Go Of The Power Button But Continue Holding The Volume Down Button Until You See The Bootloader/Recovery Screen​

Now Use The Volume Down And Volume Up Buttons To Navigate To Fastboot​

Once You Have Navigated To Fastboot Click Your Power Button To Enter Fastboot​

Connect Your HTC One M8 To Your Computer Through The USB 2.0 Drive​

Step 4A: Now Get ADB Ready To Ensure Your Device Is Connected Correctly

Continue By Going Into Your ADB/Fastboot Folder​

Hold Shift And Right Click On An Open Area​

Click Open Command Window Here​

Step 5A: Locking Bootloader And Checking Your CID

Run The Command Without The Quotes " " "adb devices"​

Your Device Number And State Should Pop Up​

Ex. F39J9q0wS830 Device

If You Don't See This Ensure You Have Done Step 2 Correctly And Try Again​

Next Run The Command Without The Quotes " " "fastboot oem lock"​

Wait About 10 Seconds To Ensure Command Goes Through And On The Command Prompt Running ADB You Should See "Success Or Okay"​

Next Run The Command Without The Quotes " " "fastboot getvar cid"​

Your CID Should Be Displayed As: T-MOB010 Or Something With "T-MOB"​

Now Run The Command Without The Quotes " " "adb reboot bootloader" Or Do It Manually​

Step 6A: Now That Is Done, Go To Your Windows Laptop And Run The RUU.exe File As An Administrator (It Takes A Few Minutes To Load)

Accept The License And Terms Agreement​

Step 7A: Now The HTC Update Utility Should Pop Up

Read The Disclaimer And Check I Understand And Click Next​

It Will Tell You To Change Your PC Screen Settings, Do Everything It Says To Do​

Since Your Phone Is Already Connected You Will Click Next​

It Will Ask Which ROM Image To Update, Just Click "Update Rom Image" Located On The Lower Middle Part Of The HTC Update Utility​

Once Done You Should See Under ROM Image, ROM Image 6.20.531.5​

Click Next And Progress With The Installation​

Leave Your Phone Alone untouched For About 10-20 Minutes​

Your Phone Will Reboot Several Times

​

Once The Update Is Finished The HTC Update Utility Will Tell You, Just Click Finish And Unplug Your HTC One M8 From Your Computer​

Your Phone Should Boot Up, If It Doesn't Just Hold Down The Power Button To Do So​

THE FIRST BOOT WILL TAKE ABOUT 4 MINUTES

​

The Boot Sequence Should Be, HTC Logo, Then T-Mobile Screen, Then HTC ONE Logo​

At Times The T-Mobile Screen Will Show After The HTC ONE Logo​

Step 8A: Now Set Up Your HTC One M8 Stock Running Android 6.0 (Marshmallow)

Just Follow The Screen Prompts​

If Your Bootloader Is Already LOCKED Follow These Steps

​

Step 3B: Boot Your HTC One M8 Into Bootloader Or Recovery Steps Below

Power Your Device Down Completely​

Click And Hold The Volume Down Button​

While Holding The Volume Down Button Use Your Other Hand And Hold In Power Button At The Same Time And Continue To Hold​

After About 5 Seconds Let Go Of The Power Button But Continue Holding The Volume Down Button Until You See The Bootloader/Recovery Screen​

Now Use The Volume Down And Volume Up Buttons To Navigate To Fastboot​

Once You Have Navigated To Fastboot Click Your Power Button To Enter Fastboot​

Connect Your HTC One M8 To Your Computer Through The USB 2.0 Drive​

Step 4B: Now Get ADB Ready To Ensure Your Device Is Connected Correctly

Continue By Going Into Your ADB/Fastboot Folder​

Hold Shift And Right Click On An Open Area​

Click Open Command Window Here​

Step 5B: Checking Your CID

Run The Command Without The Quotes " " "fastboot getvar cid"​

Your CID Should Be Displayed As: T-MOB010 Or Something With "T-MOB"​

Now Run The Command Without The Quotes " " "adb reboot bootloader" Or Do It Manually​

Step 6B: Now That Is Done, Go To Your Windows Laptop And Run The RUU.exe File As An Administrator (It Takes A Few Minutes To Load)

Accept The License And Terms Agreement​

Step 7B: Now The HTC Update Utility Should Pop Up

Read The Disclaimer And Check I Understand And Click Next​

It Will Tell You To Change Your PC Screen Settings, Do Everything It Says To Do​

Since Your Phone Is Already Connected You Will Click Next​

It Will Ask Which ROM Image To Update, Just Click "Update Rom Image" Located On The Lower Middle Part Of The HTC Update Utility​

Once Done You Should See Under ROM Image, ROM Image 6.20.531.5​

Click Next And Progress With The Installation​

Leave Your Phone Alone untouched For About 10-20 Minutes​

Your Phone Will Reboot Several Times

​

Once The Update Is Finished The HTC Update Utility Will Tell You, Just Click Finish And Unplug Your HTC One M8 From Your Computer​

Your Phone Should Boot Up, If It Doesn't Just Hold Down The Power Button To Do So​

THE FIRST BOOT WILL TAKE ABOUT 4 MINUTES

​

The Boot Sequence Should Be, HTC Logo, Then T-Mobile Screen, Then HTC ONE Logo​

At Times The T-Mobile Screen Will Show After The HTC ONE Logo​

Step 8B: Now Set Up Your HTC One M8 Stock Running Android 6.0 (Marshmallow)

Just Follow The Screen Prompts​

Congratulations You Successfully Updated Or Returned Your HTC One M8 To Stock

​

KEEP IN MIND YOU NO LONGER HAVE ROOT

​

If You Have Any Questions Or Need Help Just Comment On The Thread And I Will Reply ASAP