Develop Bugs

[Q] Bootloader Help?

When I bought my M8 off of Swappa it was already rooted and supposedly converted to the GPE edition. (Mine was the AT&T M8) I want to swtich back but what my bootloader says doesn't make sense. Anybody willing to look at it and see what's going on here?
Bootloader says:
Tampered
Unlocked
M8_UL_CA PVT SHIP S-ON
HBOOT-3.16.0.0000
RADIO-1.14.213331931.LA21G
OpenDSP-v.26.2.2-00538-M8974.0106
OS-
eMMC-boot 2048MB
Feb 27 2014,16:20:59.22987
Mainly, it isn't S-OFF and I have no CID. I have no idea what is up with this device but anyway to get it where it should?
Thanks!

ChadMan097 said:
When I bought my M8 off of Swappa it was already rooted and supposedly converted to the GPE edition. (Mine was the AT&T M8) I want to swtich back but what my bootloader says doesn't make sense. Anybody willing to look at it and see what's going on here?
Bootloader says:
Tampered
Unlocked
M8_UL_CA PVT SHIP S-ON
HBOOT-3.16.0.0000
RADIO-1.14.213331931.LA21G
OpenDSP-v.26.2.2-00538-M8974.0106
OS-
eMMC-boot 2048MB
Feb 27 2014,16:20:59.22987
Mainly, it isn't S-OFF and I have no CID. I have no idea what is up with this device but anyway to get it where it should?
Thanks!
Click to expand...
Click to collapse
Also it claims it CID (in ADB) CWM__07. Something to that note at least.

My guess is that the previous owner just flashed a GPE-based ROM, and didn't do the full conversion. I say this since the phone is S-on; and S-off is needed for the full conversion.
The radio number is also the AT&T radio, not the GPE one.
Does the phone have the AT&T logo on the back?
What happens when you boot into recovery?
I'm thinking you can just flash a ROM of your choice; or relock the bootloader and run the AT&T RUU.
ChadMan097 said:
Also it claims it CID (in ADB) CWM__07. Something to that note at least.
Click to expand...
Click to collapse
What exactly does it say for CID? AT&T CID is CWS__001, I'm guessing that is what you have.

I think that is the CID, okay that may be it. The recover is the latest of Philz Touch. The ruu always fails if I run it though, which confuses me cause I do want to run stock att room but with some rooted features is all.

ChadMan097 said:
The ruu always fails if I run it though, which confuses me cause I do want to run stock att room but with some rooted features is all.
Click to expand...
Click to collapse
Not enough info. Any error message? Did you relock the bootloader (required if S-on)?
Which RUU are you trying to run?
You can try this one: http://forum.xda-developers.com/att-htc-one-m8/general/att-2-23-502-3-bootable-ruu-pc-required-t2860486
Folks seem to have more luck with this, than the "official" .exe RUU.

Sorry for leaving some of that information out.
No, the bootloader is still unlocked, and it just comes back it couldn't do it. No error codes, just Failed to flash firmware and then you have to close it. I was trying to run the official HTC/AT&T RUU and that is the one that failed. I will try the new RUU you showed. Thanks!

Sorry for leaving some of that information out.
No, the bootloader is still unlocked, and it just comes back it couldn't do it. No error codes, just Failed to flash firmware and then you have to close it. I was trying to run the official HTC/AT&T RUU and that is the one that failed. I will try the new RUU you showed. Thanks!

ChadMan097 said:
No, the bootloader is still unlocked, and it just comes back it couldn't do it. No error codes, just Failed to flash firmware and then you have to close it. I was trying to run the official HTC/AT&T RUU and that is the one that failed. I will try the new RUU you showed. Thanks!
Click to expand...
Click to collapse
There's your problem right there. I've already stated it twice, so I'm not sure how else to get it across. Let's try it again:
You need to relock the bootloader to run the RUU since you are S-on.
This goes with the bootable RUU I linked, as well.

I got that. There was a post glitch. I have tried re-locking it, but there seems to be an ADB issue with my device as it will not correctly send commands.

ChadMan097 said:
I got that. There was a post glitch. I have tried re-locking it, but there seems to be an ADB issue with my device as it will not correctly send commands.
Click to expand...
Click to collapse
If the command "adb devices" does not return the device ID, you probably have a USB connectivity issue.
Try a different USB cable, or another USB port on your PC. Re-install HTC Sync, and if that still doesn't work, uninstall all HTC Sync and HTC drivers. Connect the phone, but do not choose the option to automatically install HTC Sync or drivers. Go to Device Manager, and find the device and manually pick the option for Generic Android MTP device (or something to that effect).

redpoint73 said:
If the command "adb devices" does not return the device ID, you probably have a USB connectivity issue.
Try a different USB cable, or another USB port on your PC. Re-install HTC Sync, and if that still doesn't work, uninstall all HTC Sync and HTC drivers. Connect the phone, but do not choose the option to automatically install HTC Sync or drivers. Go to Device Manager, and find the device and manually pick the option for Generic Android MTP device (or something to that effect).
Click to expand...
Click to collapse
I got rid of HTC sync. The drivers are fine, but sync screws stuff up.

xunholyx said:
I got rid of HTC sync. The drivers are fine, but sync screws stuff up.
Click to expand...
Click to collapse
Yes, different solutions seem to work for different PCs. And HTC Sync seems to cause more issues than its worth. Really very little benefit to Sync, aside form the fact its the most "automated" way to install the drivers.
On my work laptop, everything worked fine (adb, fastboot, MTP) on the automatically installed HTC Sync (when you attach the phone). But on my home tower PC, only adb and fastboot worked, but I could never get the internal storage to mount MTP after trying various HTC drivers, uninstalling Sync, etc. Just uninstalling everything HTC and using the Generic Android MTP drivers via Device Manager is what finally worked on that computer (everything works now, adb, fastboot, MTP).

n00b stuck on old CM because too dumb to be able to upgrade bootloader

My ATT HTC One M8 was rooted using the 'official HTC' method soon after purchase and I was able to get CyanogenMod installed via their windows install tool back in the day so I didn't have to really understand what I was doing. It still runs CM11 quite well, but I'd really like to upgrade to CM12 if for no other reasons then the security updates. When I try to upgrade to CM12 though I get this error:
This package supports bootloader(s): 3.18.0.0000, 3.19.0.00000; this device has bootloader 3.16.0.00000, Installation aborted.
My recovery is ClockworkMod Recovery v6.0.4.8
Here's my bootloader screen:
*** TAMPERED ***
*** UNLOCKED ***
M8_UL_CA PVT SHIP S-ON
HBOOT-3.16.0.0.0000
RADIO-1.16.21331931.LA11G
OpenDSP-v38.2.2-00542-M8974.0311
OS-1.58.502.1
eMMC-boot 2048MB
Apr 18 2014,16:06:33.0
I don't know what I'm doing.
After six months of occasionally messing with this I still haven't figured out how to upload the boatloader. I only barely understand the stuff I read on this site. Most things have pointed me to do this:
http://forum.xda-developers.com/htc-one-m8/development/firmware-flashing-panic-attacks-t2824048
But I'm not s-off, there is a ton of downloads and steps and 150 pages of comments (!) so if there is something burried in there that will help me I can't find it. I tried blindly applying one of the firmware downloads but it didn't work. and it was probably the wrong one anyway.
Everything else pointed me to return to stock and accept the OTA update with this thread:
http://forum.xda-developers.com/showthread.php?t=2696282
But I again got lost, and never got this working. Once I got brave and spent the better part of a day trying to return everything to stock, but I couldn't figure out how to do it in the end and was super-happy to get back where I started and have a working phone again. I don't recall the exact problem I had, but I remember trying several RUUs - not being sure which one was the right one - and they wouldn't apply and that was after changing recovery versions and types several times and following random forum advice and thinking I bricked the thing a dozen times.
My question is: Is there a simple way to upgrade my bootloader ? Simple meaning exact steps to follow to just upgrade the bootloader without doing a bunch of other stuff that could brick me and I don't understand? I'm not really sure where to begin, even though I've tried a bunch of stuff, this stuff is so confusing.
Is there any help for noob like me?

You have AT&T - those threads are not for you.
You need to see this - http://forum.xda-developers.com/showthread.php?t=2751432
1. Download RUU 4.28.502.2 RUU
2. Boot your device to bootloader/fastboot and connect to PC
2. relock bootloader - command fastboot oem lock
3. Install RUU
4. re-unlock your bootloader with the unlock_code.bin that you got from HTCDev
5. reinstall custom recovery
6. install your preferred custom ROM
To run a RUU .. you need USB2.0 and latest HTC USB driver installed. If not sure, download HTC Sync Manager - http://www.htc.com/us/support/software/htc-sync-manager.aspx
install it as it will install the latest HTC USB driver then uninstall the HTC Sync Manager but leave the driver.
This will wipe everything on internal storage - backup your photos, musics & etc to PC first.

Wow, thanks for taking the time with specific steps and links! I'll try again this weekend and let you know!

thanks!
This worked perfect! I think the key was the ATT RUU, which I definitly wasn't using it before. Once done getting back to CM was a snap and I'm now in great shape! Thanks so much!

You're welcome.
Correct RUU for correct device always fix things

S-On Problem

Hey guys,
I have an unlocked At&T M8 which I'm currently using in the UK, but for some reason won't receive OTA updates (still stuck on 4.4.3). HTC Sync doesn't seem to work either, with it stuck on 'loading data'. So I stupidly decided to flash a rom without backup...
Since my hboot is still 3.16, WiFi doesn't work on any with any of the roms i have flashed. Is there anything I can try to at least get the WiFi working without paying $25 for sunshine? I can't seem to find a rom that supports 1.x firmware; if anyone could point me in the direction that would be awesome.

mrzebracookie said:
Hey guys,
I have an unlocked At&T M8 which I'm currently using in the UK, but for some reason won't receive OTA updates (still stuck on 4.4.3). HTC Sync doesn't seem to work either, with it stuck on 'loading data'. So I stupidly decided to flash a rom without backup...
Since my hboot is still 3.16, WiFi doesn't work on any with any of the roms i have flashed. Is there anything I can try to at least get the WiFi working without paying $25 for sunshine? I can't seem to find a rom that supports 1.x firmware; if anyone could point me in the direction that would be awesome.
Click to expand...
Click to collapse
Run the AT&T RUU. Personally, I would gain S-Off and convert to WWE/Europe. But the RUU is your best second option.
You can find the RUU and instructions on how to update your system manually on the official US HTC website. Link here.
Realize that RUNNING THE RUU WILL WIPE YOUR PHONE!!! So make sure to backup anything that is important to you.

xunholyx said:
Run the AT&T RUU. Personally, I would gain S-Off and convert to WWE/Europe. But the RUU is your best second option.
You can find the RUU and instructions on how to update your system manually on the official US HTC website. Link here.
Realize that RUNNING THE RUU WILL WIPE YOUR PHONE!!! So make sure to backup anything that is important to you.
Click to expand...
Click to collapse
Thank you, however HTC sync doesn't work so I downloaded the RUU from the link. The installer automatically shuts off after I accept licensing (I have relocked bootloader and put the phone in fastboot mode). The only PC in my house is running windows 8.1 :crying:
I even tried this guide http://forum.xda-developers.com/showthread.php?t=2735235, but windows won't let me open the rom.zip. Is there another way to flash the RUU on to my phone?
Also, do I need to download a recovery image if I'm using the RUU?

mrzebracookie said:
Thank you, however HTC sync doesn't work so I downloaded the RUU from the link. The installer automatically shuts off after I accept licensing (I have relocked bootloader and put the phone in fastboot mode). The only PC in my house is running windows 8.1 :crying:
Click to expand...
Click to collapse
Its a somewhat common issue. Might be the Win version, or USB 3.0 ports. If your PC has USB 3.0 ports, I saw a user mention you can turn off this function (make them 2.0) and that seemed to help the RUU.
Otherwise, you might need to borrow a friend's PC.
mrzebracookie said:
I even tried this guide http://forum.xda-developers.com/showthread.php?t=2735235, but windows won't let me open the rom.zip. Is there another way to flash the RUU on to my phone?
Click to expand...
Click to collapse
That guide is very clear what CIDs it works for, and yours is not one of them.
mrzebracookie said:
Also, do I need to download a recovery image if I'm using the RUU?
Click to expand...
Click to collapse
No

redpoint73 said:
Its a somewhat common issue. Might be the Win version, or USB 3.0 ports. If your PC has USB 3.0 ports, I saw a user mention you can turn off this function (make them 2.0) and that seemed to help the RUU.
Otherwise, you might need to borrow a friend's PC.
That guide is very clear what CIDs it works for, and yours is not one of them.
No
Click to expand...
Click to collapse
Thank you for the help. I got the RUU to work on a computer running Windows 7.
I know I have to relock the bootloader to have the RUU work, but the computer, and thus RUU, doesn't detect my phone in fastboot after relocking my bootloader. Fastboot displays 'fastboot USB', but the RUU doesn't detect anything. Before relocking, the computer detected my phone.
I have installed the latest HTC sync manager, so all the drivers should be installed.

mrzebracookie said:
Thank you for the help. I got the RUU to work on a computer running Windows 7.
I know I have to relock the bootloader to have the RUU work, but the computer, and thus RUU, doesn't detect my phone in fastboot after relocking my bootloader. Fastboot displays 'fastboot USB', but the RUU doesn't detect anything. Before relocking, the computer detected my phone.
I have installed the latest HTC sync manager, so all the drivers should be installed.
Click to expand...
Click to collapse
I can't tell if you are asking for more help, or just making a comment (and the RUU ran successfully)?
Having the bootloader locked, relocked or unlocked should have no bearing on whether fastboot connects or not. I think something else is/was going on, and the bootloader lock is just a false symptom/condition.

how do i turn my htc one m8 with s-off TO worldwide europe ?

can't say better :
how do i turn my htc one m8 with s-off TO worldwide europe ?
thx

Depends on which M8 model you have!
Which begs the question... which M8 model do you have?

shirreer said:
Depends on which M8 model you have!
Which begs the question... which M8 model do you have?
Click to expand...
Click to collapse
It is carrier branded device - T-Mobile Poland
CID T-MOB009
MID 0P6B10000
( ckpv5 helped me to find out )
i've used the sunshine app,and now my phone is s-off and rooted permanently ( i done the thing with the token given by htc-dev)

You could have continued here
http://forum.xda-developers.com/showthread.php?t=3286905
But if you want the wwe (latest firmware 4.16.401.13) than download that firmware, fastboot flash it twice and install any of the latest roms. Or run the 4.16.401 RUU.
Or if you want the developers edition up to MM then you can go for that firmware.
Edit :
The phone is not rooted permanently, it's unlocked (bootloader) permanently. Root itself is at OS level and is only achieved when you flash a superuser.zip via the custom recovery or install a pre rooted custom rom !

Fine.
A long and excruciating, nested multi-step process awaits:
Fortunately, your MID needs no modification, so without further ado:
1. You need to change your CID from T-MOB009 to HTC__001:
A. Connect your phone to your computer, boot into bootloader, and go to fastboot.
B. Launch adb on your computer and type (note: there are two underscores, and total 8 characters to the CID):
fastboot oem writecid HTC__001
C. reboot your phone into bootloader and check out your new CID (adb getvar all).
2. Flash the latest available WWE official RUU (stock android 5.0/Sense 6):
http://forum.xda-developers.com/htc-one-m8/general/htc-one-m8-european-signed-ruu-0p6bimg-t2911563
3. For best results, from my experience, flash that RUU twice, then let it boot, then do a hard-reset from settings.
4. Get coffee.
5. Set yourself up all over again.
6. Profit

shirreer said:
2. Flash the latest available WWE official RUU (stock android 5.0/Sense 6):
http://forum.xda-developers.com/htc-one-m8/general/htc-one-m8-european-signed-ruu-0p6bimg-t2911563
Click to expand...
Click to collapse
All OP files there are dead links

Here are 4.16.401.10 ruu files
http://forum.xda-developers.com/showthread.php?p=64434617

ckpv5 said:
All OP files there are dead links
Click to expand...
Click to collapse
You're too fast! It's like you're waiting for me to post that dead link Fine. Get this one:
http://androidruu.com/getdownload.p...6G_20.68.4196t.01_F_release_417003_signed.exe

Nah .. I just switch on my PC and I saw the post on top

:laugh: thank you guys , i'm gonna try to do this in the calm way
is still have to make Android ADB interface recognized properly by Win 10.
it gonna be fine , thansk all.

A good number of RUUs are available here:
http://androidruu.com/?developer=M8
@amif7
While I'm merely a helpful rookie, you're very lucky to have the illustrious Mr. Hofs here to help you. He's one of XDA's elite. Hats off

thanks all , hope it will help others with all that precisions.
:good:

shirreer said:
A good number of RUUs are available here:
http://androidruu.com/?developer=M8
@amif7
While I'm merely a helpful rookie, you're very lucky to have the illustrious Mr. Hofs here to help you. He's one of XDA's elite. Hats off
Click to expand...
Click to collapse
Meh. Not as much as i was on the HTC One X

amif7 said:
is still have to make Android ADB interface recognized properly by Win 10.
Click to expand...
Click to collapse
Yes, that is the only way to change CID.
Also, if you use the RUU.exe, you need fastboot interface, which goes hand in hand with adb. However, if you use the RUU zip method (put it right on the phone and boot into bootloader) than you won't need fastboot to do that.

i've done everything and i'm now at the step i try to flash my cell with RUU you've told me.
"RUU_M8_UL_L50_SENSE60_MR_HTC_Europe_4.16.401.10_Radio_1.25.214500021.06G_20.68.4196t.01_F_release_417003_signed"
but problem that has been 30 minutes the status " update" of the wizard with 0/7 update was sent to my phone.
arghh..xd
edit : cid was succesfuly changed to htc__001

Disconnect the phone and try again. This just happens sometimes (its been reported, then works on the subsequent try). Put the phone in bootloader-fastboot mode, if you haven't already tried that.
If it still hangs, you might need to use a different computer. Win7 and USB 2.0 for the best chance of success. RUU is finicky with some computers.

amif7 said:
i've done everything and i'm now at the step i try to flash my cell with RUU you've told me.
"RUU_M8_UL_L50_SENSE60_MR_HTC_Europe_4.16.401.10_Radio_1.25.214500021.06G_20.68.4196t.01_F_release_417003_signed"
but problem that has been 30 minutes the status " update" of the wizard with 0/7 update was sent to my phone.
arghh..xd
edit : cid was succesfuly changed to htc__001
Click to expand...
Click to collapse
Either:
A. Without canceling the ruu process, go to the root of your C: drive and search for Rom.zip file; copy it to your desktop, and rename it to 0P6BIMG.zip (first character is zero, and careful not to rename it to 0P6BIMG.zip.zip). Copy this file to the root of your phone's SD Card. Then, boot your phone into bootloader. Proceed with the on-screen instructions.
Or:
B. Cancel the ruu process, unplug your phone, download & install HTC Sync Manager from HTC's M8 support page. Reboot your PC, plug in your phone and wait until Windows installs the drivers. Start the RUU again and proceed to flashing.
Cheers
P.S. I trust you'll give us feedback about this.
---------- Post added at 08:59 PM ---------- Previous post was at 08:58 PM ----------
Mr Hofs said:
Meh. Not as much as i was on the HTC One X
Click to expand...
Click to collapse
Those were good days, too bad nvidia messed it up. I remember you from back then.
Cheers

shirreer said:
Either:
A. Without canceling the ruu process, go to the root of your C: drive and search for Rom.zip file; copy it to your desktop, and rename it to 0P6BIMG.zip (first character is zero, and careful not to rename it to 0P6BIMG.zip.zip). Copy this file to the root of your phone's SD Card. Then, boot your phone into bootloader. Proceed with the on-screen instructions.
Or:
B. Cancel the ruu process, unplug your phone, download & install HTC Sync Manager from HTC's M8 support page. Reboot your PC, plug in your phone and wait until Windows installs the drivers. Start the RUU again and proceed to flashing.
Cheers
P.S. I trust you'll give us feedback about this.
---------- Post added at 08:59 PM ---------- Previous post was at 08:58 PM ----------
Those were good days, too bad nvidia messed it up. I remember you from back then.
Cheers
Click to expand...
Click to collapse
Those were good days, too bad nvidia messed it up. I remember you from back then.
Click to expand...
Click to collapse
I don't understand the sentence here with nvidia ??

amif7 said:
I don't understand the sentence here with nvidia ??
Click to expand...
Click to collapse
The comment wasn't related to your issue (just a side comment). It was in response to Mr Hofs post about his presence on the One X (different phone) forum. The One X (ENDEAVORU) had its chipset supplied by NVIDIA, which created some video issues for that phone.
EDIT: Better description of the NVIDIA issue in shirreer's response below.

amif7 said:
I don't understand the sentence here with nvidia ??
Click to expand...
Click to collapse
That was meant for Mr. Hofs. The One X was HTC's 2012 flagship*(preceeding the One M7). It ran Android ICS & Sense on NVIDIA quadcore Tegra SoC. Unfortunately, HTC couldn't keep it up-to-date (and, eventually, ended its lifecycle prematurely) mainly because NVIDIA failed to provide it with system software and drivers. Next year, HTC went with Qualcomm and never looked back.
And, then...
Aren't you supposed to be focusing on the other thing?!?

HTC M8 Downgrading

Dear XDA developers, professionals and programmers:
Recently I came across a good deal (HTC M8 in mint condition) and bought it. It was running Android 4.4.4 and I was happy with it till I read that it could be updated to Marshmallow. I followed a few links and after some time discovered that it was originally bought from the USA and locked to AT&T even though the installed rom was WWE. Stupidly I downloaded Marshmallow update for AT&T (RUU) from the HTC website and ran the installer. The installer completed successfully and the phone now runs Marshmallow with Sense7.
Since the rom was filled to brim with useless AT&T crap that does not work outside AT&T network I decided to switch to developer WWE rom but the RUU refused to install on the phone (I have S-Off)
After doing a bit more reading I discovered it was because my new rom has a software number 6.20.502.5 while the RUU I would like to install has a software number of 6.12.1540.4
I googled and googled and searched and searched but could not find a single tutorial to explain how I can replace my current rom with the WWE version which has less bloatware and takes it easy on the RAM.
Can someone kindly explain (or redirect me to a link) of how to downgrade HTC M8 from image version 6.20.502.5 to image version 6.12.1540.4 or in layman's terms how to replace AT&T rom with Developer rom? BTW both roms are Marshmallow. I do not wish to install TWRP or CM so if there is a way besides this I'd be grateful. If not then I don't see any other options and I'd still be grateful
Awaiting your generous replies

What you want is not really a "downgrade" per se. While the AT&T version number is "larger" than the Dev Ed (6.20 versus 6.12), that is mostly just because it came later due to AT&T's slowness in approving the software. I don't think there is much (if anything) that is actually "newer" or "updated" in the AT&T stock ROM (versus Dev Ed). It just has (as you know) all the AT&T branding and bloatware crap.
What is keeping you from flashing the Dev Ed RUU 6.12.1540 is that your carrier ID (CID) needs to match the RUU (even with s-off). Therefore, you need to change your CID to that of the Dev Edition (or alternately SuperCID), which is easy since you already have s-off. You will however need root to do this, so either flash TWRP and SuperSU/Magisk to root, or you can run adb shell with run while booted to TWRP. Either way, you will need to install TWRP: https://forum.xda-developers.com/htc-one-m8/general/change-wwe-m8-to-dev-edition-ota-t2826567
No need to change the Model ID (MID) since the AT&T version and Dev Edition have the same MID.
After that, you should be able to run the Dev Ed RUU.

Sorry .. correction. No need root/twrp to change CID, only change MID need these.
Simply reboot to bootloader/fastboot then run command
To Dev Ed CID
fastboot oem writecid BS_US001
To SuperCID
fastboot oem writecid 11111111
Can't remember if this only can be done on unlocked bootloader. If can't, try this command first
fastboot oem rebootRUU
the follow by the above.
If still can't then need a unlocked bootloader to proceed.

ckpv5 said:
Sorry .. correction. No need root/twrp to change CID, only change MID need these.
Click to expand...
Click to collapse
Ah yes, obviously I was mixing up my methods to change CID versus MID.
Thanks for clarifying, yet again.

Thank you
Many thanks to you gentlemen for your generous assistance and helpful instructions. I really appreciate it. All the best

Update
Good day all:
Sorry to bother again but it failed again! I downloaded fastboot adb and followed the procedure, put the phone in fastboot mode and the CID was already 11111111 and still it refused to accept the RUU. Please find attached a photo of my fastboot screen, hope it can help determine where the problem is on my phone. [ The following errors occurred with your submission:
To prevent spam on the XDA forums, ALL new users prevented from posting outside links in their messages. After approximately 10 posts, you will be able to post outside links. Thank you for understanding!] Site refused to allow me to attach the photo link so I'll just write everything here
*****Software Status - Official******
******LOCKED******** (Even though I can use a non AT&T sim normally)
MS_UL_CA PVT SHIP S-OFF
CID~11111111
HBOOT - 3.19.0.0000
Radio - [email protected](long number)
OPENDSP - v56.2.2. (loooooooong number)
OS-6.20.502.5
eMMC Boot - 2048MB
*end of pic*
On the official HTC site in the support section where they post the RUUs it states the following.
"Before you proceed, please confirm that this software upgrade to 6.12.1540.4 is a newer version than what is currently loaded on your device. If it is the same version, there is no need to reload the software. Navigate to the Home screen then tap All apps > Settings > About and locate the Software information . If your Software number is less than 6.12.1540.4 , you should proceed with the upgrade." end of quote
This paragraph is what let me to believe it is the software version that is stopping me from changing RUUs and why I called this post a downgrade (even though I know it's not)
Can any of you good gentlemen help me out a bit more? I'm willing to answer any questions to further clear the picture of my predicament.
Thank you again

Bootloader is fine, still ATT.
Explain more on the error that you have when you tried installing RUU.
Do note - to run RUU you need PC with USB 2.0;
Latest htc usb drivers which you'll get when you installed latesr htc sync manager (uninstall sync manager but leave all drivers to proceed RUU installation)

ckpv5 said:
Bootloader is fine, still ATT.
Explain more on the error that you have when you tried installing RUU.
Do note - to run RUU you need PC with USB 2.0;
Latest htc usb drivers which you'll get when you installed latesr htc sync manager (uninstall sync manager but leave all drivers to proceed RUU installation)
Click to expand...
Click to collapse
Thank you for your reply:
the RUU I'm trying to install is the developer RUU that I downloaded off the HTC official website. It is the same website I downloaded the AT&T RUU from which installed fine, upgrading the phone's OS from Android 4.4.4 to Android 6.0.
I have several laptops each running a different OS (Windows 7 which I use mostly and have been using for this process) Windows 10, Linux and Solaris.
I did download and install HTC Sync but disabled it's auto run when I noticed every time I plug my phone in it pops up. So that's disabled not uninstalled, but it didn't interfere in the RUU installation of the ATT update and it doesn't pop up when I try to install the developer update.
The Error get is as follows:
Upon running the RUU it does all the necessary checks and then asks me if I would like to install the update, I click on "I Agree" and next, then it puts the phone in boot mode (black screen with HTC written in grey) and after it begins the process by popping up a screen that says: Current info about your Android phone: Image Version: 6.20.502.5 select one below and the update button. After I click on it another screen pops up: Verify that you want to update the Rom version from image version 6.20.502.5 to image version 6.12.1540.4 Clicking on Next another windows shows explaining what happens when I click on Next. When I click next it puts the phone in boot mode and begins by Reading header, sending............................................. then it pops another screen that says update failed and I have to click on recovery and press the power button on my phone for 10 seconds to turn it off

Sir Lucifer said:
On the official HTC site in the support section where they post the RUUs it states the following.
"Before you proceed, please confirm that this software upgrade to 6.12.1540.4 is a newer version than what is currently loaded on your device. If it is the same version, there is no need to reload the software. Navigate to the Home screen then tap All apps > Settings > About and locate the Software information . If your Software number is less than 6.12.1540.4 , you should proceed with the upgrade." end of quote
This paragraph is what let me to believe it is the software version that is stopping me from changing RUUs and why I called this post a downgrade (even though I know it's not)
Click to expand...
Click to collapse
You can't really take the "official" HTC info literally, anymore. By having s-off and SuperCID, you are so far off the "official" path, that most of the rules no longer apply.
S-off bypasses version check (flashing older RUUs is allowed). In fact, you can RUU all the way back to Kitkat if you wanted with s-off (not recommended - just making a point).
---------- Post added at 09:56 AM ---------- Previous post was at 09:52 AM ----------
Sir Lucifer said:
The Error get is as follows:
Upon running the RUU it does all the necessary checks and then asks me if I would like to install the update, I click on "I Agree" and next, then it puts the phone in boot mode (black screen with HTC written in grey) and after it begins the process by popping up a screen that says: Current info about your Android phone: Image Version: 6.20.502.5 select one below and the update button. After I click on it another screen pops up: Verify that you want to update the Rom version from image version 6.20.502.5 to image version 6.12.1540.4 Clicking on Next another windows shows explaining what happens when I click on Next. When I click next it puts the phone in boot mode and begins by Reading header, sending............................................. then it pops another screen that says update failed and I have to click on recovery and press the power button on my phone for 10 seconds to turn it off
Click to expand...
Click to collapse
The RUU stalling out while "sending" is a common bug. Did you simply try running the RUU again? A lot of times, it will work on subsequent attempts.
The fact it got that far, means to me that it passed (or bypassed) any version or CID checks. Otherwise, it never would have gotten to the point of "sending". Instead, it would have told you something like "Error 140" with a description of what the problem was, and aborted the install before ever "sending".

redpoint73 said:
You can't really take the "official" HTC info literally, anymore. By having s-off and SuperCID, you are so far off the "official" path, that most of the rules no longer apply.
S-off bypasses version check (flashing older RUUs is allowed). In fact, you can RUU all the way back to Kitkat if you wanted with s-off (not recommended - just making a point).
---------- Post added at 09:56 AM ---------- Previous post was at 09:52 AM ----------
The RUU stalling out while "sending" is a common bug. Did you simply try running the RUU again? A lot of times, it will work on subsequent attempts.
The fact it got that far, means to me that it passed (or bypassed) any version or CID checks. Otherwise, it never would have gotten to the point of "sending". Instead, it would have told you something like "Error 140" with a description of what the problem was, and aborted the install before ever "sending".
Click to expand...
Click to collapse
Have tried it 5 times already, results are the same. I'm downloading the RUU again, maybe my download was corrupt. Will get back to you later with any results. Thank you for your patience and time. Much appreciated

redpoint73 said:
You can't really take the "official" HTC info literally, anymore. By having s-off and SuperCID, you are so far off the "official" path, that most of the rules no longer apply.
S-off bypasses version check (flashing older RUUs is allowed). In fact, you can RUU all the way back to Kitkat if you wanted with s-off (not recommended - just making a point).
---------- Post added at 09:56 AM ---------- Previous post was at 09:52 AM ----------
The RUU stalling out while "sending" is a common bug. Did you simply try running the RUU again? A lot of times, it will work on subsequent attempts.
The fact it got that far, means to me that it passed (or bypassed) any version or CID checks. Otherwise, it never would have gotten to the point of "sending". Instead, it would have told you something like "Error 140" with a description of what the problem was, and aborted the install before ever "sending".
Click to expand...
Click to collapse
Maybe my downloaded RUU is corrupt, I'll download another time and if it gives me the same problem I'll look for another source. I will keep you posted, thank you very much good man.

RUU Broken on HTC's website
Dear all:
After downloading the developer RUU for the second time and trying to install it again (Marshmallow for those of you who have just joined us) off the HTC support site I failed miserably at changing my firmware using that RUU. After a series of searches on the internet and darknet I came across a post on reddit dot com titled M8 marshmallow RUU from HTC is broken and the article was dated last year. Searching further I found a similar post on a Chinese website that stated the same thing. So in conclusion the developer RUU on HTC's site is damaged as confirmed by a few users/developers on both reddit and the Chinese website.
Sorry for wasting all your time gentlemen. I am very grateful (and very lucky) having assistance from good people like yourselves who have taken from their time to help a complete stranger. Much obliged gentlemen. And thank you all again

Cannot be the RUU is broken.
Another way to do this :
1. Install Dev Edition firmware. You can get the fw_6.12.1540.4.zip from - https://forum.xda-developers.com/showpost.php?p=60218734&postcount=5
2. Instead of using RUU exe, you can use RUU zip (rom.zip) to install RUU. I remember long time ago someone had same problem like you. Asked him to use zip format RUU and it was successful.
I believe there is RUU.zip somewhere on XDA. Can't search now as I'm on mobile.
You can get your own RUU.zip which is actually rom.zip yourself. Just run RUU.exe (no need to connect phone). Once it opens the agreement page, go to %temp% thru your search/run windows menu.
It's better to clear your temp directory first so easy to find 2 newly created folder when you run RUU.exe
The rom.zip is inside one of the folder. Copy that to your desktop.
Then follow this on how to install - https://forum.xda-developers.com/showpost.php?p=64926626&postcount=6
There are 3 methods but I prefer the htc_fastboot because easily can see any error if any.
So step 1 firmware & step 2 RUU (rom.zip)

Sir Lucifer said:
Dear all:
After a series of searches on the internet and darknet I came across a post on reddit dot com titled M8 marshmallow RUU from HTC is broken and the article was dated last year. Searching further I found a similar post on a Chinese website that stated the same thing. So in conclusion the developer RUU on HTC's site is damaged as confirmed by a few users/developers on both reddit and the Chinese website.
Click to expand...
Click to collapse
Did those threads specifically mention RUU 6.12.1540.4? If not, then you realize this device has dozens of RUUs for the M8? Most of which have been confirmed many times over to work properly.
My experience, is that 95% of the time, the problem with RUU running is with the PC. Try re-installing HTC drivers, different USB port, turn off USB 3.0. Also try a different USB cable, or if possible another PC.
Downloading the RUU again (as you tried) is not a bad idea. They do sometimes get corrupted while downloading. But if you download another time, and it still fails, the problem is probably not the RUU.
You should also verify your PC has Visual C++ installed, as the RUU exe requires it. The error your are encountering doesn't sound like the C++ problem. But it won't hurt to verify, anyway. Link here, but confirm it's the right install for your Windows version: https://forum.xda-developers.com/showpost.php?p=60021580&postcount=4
Or of course, you can use the RUU.zip method stated by ckpv5, which avoids all the of the above possible pitfalls. You'll need to search for the 6.12.1540.4 zip, as I don't know where it is off hand, either.

Downloaded Again
redpoint73 said:
Did those threads specifically mention RUU 6.12.1540.4? If not, then you realize this device has dozens of RUUs for the M8? Most of which have been confirmed many times over to work properly.
My experience, is that 95% of the time, the problem with RUU running is with the PC. Try re-installing HTC drivers, different USB port, turn off USB 3.0. Also try a different USB cable, or if possible another PC.
Downloading the RUU again (as you tried) is not a bad idea. They do sometimes get corrupted while downloading. But if you download another time, and it still fails, the problem is probably not the RUU.
You should also verify your PC has Visual C++ installed, as the RUU exe requires it. The error your are encountering doesn't sound like the C++ problem. But it won't hurt to verify, anyway. Link here, but confirm it's the right install for your Windows version: https://forum.xda-developers.com/showpost.php?p=60021580&postcount=4
Or of course, you can use the RUU.zip method stated by ckpv5, which avoids all the of the above possible pitfalls. You'll need to search for the 6.12.1540.4 zip, as I don't know where it is off hand, either.
Click to expand...
Click to collapse
I did download the developer RUU again, I also downloaded the Metro PCS RUU which has a software number of 6.20.531.5 and it installed just fine but refused to see the sim card so I reinstalled AT&T
I am an electronics engineer so yes my laptops are always up to date on flash, oracle, C++, Perl, Java, etc

ckpv5 said:
I believe there is RUU.zip somewhere on XDA. Can't search now as I'm on mobile.
Click to expand...
Click to collapse
redpoint73 said:
You'll need to search for the 6.12.1540.4 zip, as I don't know where it is off hand, either.
Click to expand...
Click to collapse
Sir Lucifer said:
I did download the developer RUU again, I also downloaded the Metro PCS RUU which has a software number of 6.20.531.5 and it installed just fine but refused to see the sim card so I reinstalled AT&T
I am an electronics engineer so yes my laptops are always up to date on flash, oracle, C++, Perl, Java, etc
Click to expand...
Click to collapse
I have the RUU.zip
You can download it from here :good:

Sir Lucifer said:
I also downloaded the Metro PCS RUU which has a software number of 6.20.531.5 and it installed just fine but refused to see the sim card so I reinstalled AT&T
Click to expand...
Click to collapse
That is the T-Mobile RUU. MetroPCS merged with T-Mobile, so it's a bit one and the same. But most everyone will call that RUU/version T-Mobile. It will change band support (as flashing any other RUU will). So if it was working before on the AT&T RUU(or Dev ED will support the same bands) I would not mess with random RUUs, unless we suggest them specifically.