pretty simple as the title states is there a way to go back to a stock unrooted firmware?
Flash the production RUU file, just like the downgrade step in the rooting process.
You'll rename is, place it on the SD card, reboot to fastboot and load bootloader. It should flash the pg05img.zip and it will be back to when you bought it.
sorry i should have mentioned what i have tried..
I am pretty sure i tried that... the file i flashed was some 459MB's is that the right one or should have have reflashed the one that is like 399MB's.. when i tried the larger file it went through the process but it said something like main is newer or something and wouldn't do anything and when i rebooted it nothing had changed..
One Last HTC Thunderbolt Software Update Leaks Before Launch - Droid Life: A Droid Community Blog this should be the correct firmware.
If you're still having trouble I'd go talk to the andIRC guys over at xda
I am still a little bit weary about rooting this phone till a proven unroot method has come up and is posted. It was pretty simple back in the OG Droid launch days but I am not as confident with the thunderbolt.
i tried just reflashing the downgrade firmware alone (most of step 4) and that didn't work so i did steps 1-3 then just the flashing part of step 4.. That worked except i was on the old software so i looked at the link he posted which is apparently a very new firmware, so i just found a non-chinese link then downloaded it and reflashed and now all is back to stock and i have a new software number (1.12.605.9) which is newer than the one that comes on the phone from verizon..which you can download here ( MultiUpload: Multiupload.com - upload your files to multiple file hosting sites! ) without having to decipher some chinese website. then Rename it PG05IMG.zip, drop it on the sdcard, reboot and hold down volume down