I had a problem similar to this before when I was trying to unlock and root my One, so I thought I was fix it the same way I did then. I downloaded the vzw m7 RUU from here and installed it using fastboot. The RUU installs just fine and everything in the command prompt says that it was successful. But when I try to boot my phone now, it hangs on the white htc splash screen.
It also hangs on the white htc splash screen when I try to enter recovery. I'm at a loss, and I am now thinking I may have gained a new paperweight today. Has this ever happened to anyone? Or does anyone know how to fix this?
If it helps, this is what I see on my bootloader:
m7_wlv pvt ship s-off rh
UPDATE: Okay, so I tried installing instead the 2.10.605.1 RUU (I had been using the 1.10 version before) and now instead of hanging at the white htc splash screen, it shows the slpash screen for a few seconds and then goes back to the bootloader saying "Active cmdline overflow! (1073 Bytes)" This is new... any ideas?
UPDATE2: I googled the Active cmdline overflow problem and saw that for some it worked to downgrade hboot to 1.44. I got the hboot zip from here. And now no more Active cmdline problem! YAY! Only now my phone is once again hanging on the white htc slpash screen.
UPDATE3: Haven't done anything else since the last update, but I did just notice that when I try to boot into recovery, I get a black screen with a picture of an phone with a red triangle on it. I get a similar screen when I try to boot into "Factory Reset" but instead of a red triangle there are two green arrows making a circle. Also when my phone is plugged in my phone now once again shows the charging animation (phone turned off). This was not the case before.