Any help with my HTC M8 appreciated.

[DABOSS]

Please excuse my ignorance I have read many post on this forum regarding my model however I am completely lost and have no idea of where I am or which part of my mobiles software I should be attempting to fix.
My phone was working fine it just went away into the draw after I upgraded to a newer handset about 18 months ago. I wanted to use it as a second mobile a few month back but when I powered it up it started be having weird. It would load ok but the back button just disappear as it isn't a physical button and one on the screen I could not operate the phone properly as it just was not there. I realized that if the phone stayed on for a while it began to get warm on the back also.
I put the phone away and thought id get to it another time as I did have some old photos I wanted that I know were stored on the phone memory the sd card ones I have already.
today I chucked it on the charger and it failed to boot up properly.
I cant get past the HTC boot up screen
I get one of either screens the htc page a black back lit screen saying cant load sence home has stopped and then stays there
if i play with the power and vol buttons I can get into boot screen and thats it.
there is also a brief moment where i was able to read in red writing this message "this build is for development purposes only do not distribute outside of HTC.
I have never tried to modify the software on my device.
It was bought in the UK from Vodafone store new

Id apprechiate if anyone is able to guide this old man to recover his old mobile


the following is what I can get up on the screen
***Software status: Modiffied ***
*** Locked ***
*** Security Waring ***
M8_UL PVT SHIP S-ON
HBOOT-3.19.0.0000
RADIO-1.25.214500021.06G
OPENDSP-V48.2.200564-M8974_F0.1211
OS-4.19.161.3
eMMC-boot 2048MB
Aug 4 2015, 21:56:12.0

Thank you for any help you may offer.

 

[redpoint73]

Some part of the OS probably became corrupted while it was powered off for 18 months, thus "tripping" the Modified Software flag, and red text warning.

Steps to re-install the OS will wipe any data on the phone, so the old photos are almost certainly not possible to be recovered. So the only feasible way forward is to make the phone operable again (working OS) as a second mobile (as you mentioned); rather than recovery photos or any other personal data from it.

To that goal, you can try the following RUU, which would be the easiest way to get the phone running. Download the RUU to PC, connect the phone, and then run the RUU executable, and it will walk you through the rest:
https://androidfilehost.com/?fid=95916177934555497

One caveat, is that you normally can't run an "older" version RUU (lower number than OS version currently installed)) and the RUU ends in "2" where your OS number ends in "3". But I think it still might work, since the version numbers are very close (different number at the beginning of the OS number is a different story) and will actually read as the "same" version. And I did find the RUU posted in response to a request for RUU for your same OS number (4.19.161.3) here: http://forum.gsmhosting.com/vbb/11601146-post251.html

In any case, it doesn't hurt to try the RUU. Worst case, it fails to due version check, and does not install the RUU.

Again, if the RUU installs, it will wipe all personal data on the phone.

 

[DABOSS]

Hi Redpoint73, Thank you very much for you detailed reply. I have only now been able to have a chance to recover my mobile however after much headace trying to download the files because the browsered saw them as a potential threat due to the .exe extenstion. Now I have the 1.2gb file on my desktop when I try run I just get a MS error Installscript setup launcher has stopped working. been at it for a while but I dont know what to do past this. Thanks for your assistance if you think of anything else I will give it a go thank you.

Should I have anyother software installed on the machine other than the htc sync manager

 

[redpoint73]

Now I have the 1.2gb file on my desktop when I try run I just get a MS error Installscript setup launcher has stopped working. been at it for a while but I dont know what to do past this. Thanks for your assistance if you think of anything else I will give it a go thank you.

Should I have anyother software installed on the machine other than the htc sync manager

Need to have Visual C++ installed on the PC, which may be causing the crash: https://forum.xda-developers.com/showpost.php?p=53166955&postcount=97

Needs to be a native PC, not a emulated Mac, etc.

Also, Windows XP and Windows 7 may have more luck than Win8, 10. But not always an option for some folks, of course.