HTC One (m7ul) not found by ADB + formatted filesystem = bricked? So, I'm really hoping that I haven't bricked my phone and that someone can help me figure out how to fix this.

I can't remember exactly the steps I took to mess it up so spectacularly, but they included trying to flash to the M2 snapshot of CyanogenMod 11 from a ViperOne ROM, relocking the bootloader, attempting to restore to a stock RUU (and failing because I accidentally downloaded an unsigned version), reUNlocking the bootloader, and formatting via TWRP.

Fastboot appears to recognise that the phone is plugged in (it reads FASTBOOT USB on the bootloader screen), and Windows 8 sees the device in Device Manager. However, when I attempt to do anything with ADB it returns error: device not found, so I can't use rebootRUU or push files to the /sdcard/ directory, and I have no ROMs to flash.

The bootloader screen reads:

*** TAMPERED ***
*** RELOCKED ***
*** Security Warning ***
M7_UL PVT SHIP S-ON RH
HBOOT-1.54.0000
RADIO-4A.17.3250.14
OpenDSP-v31.120.274.0617
OS-2.24.841.1
eMMC-boot 2048MB
Jun 21 2013,23:03:15.0

FASTBOOT USB


It also appears that I am able to use FastBoot to lock and unlock the bootloader using the unlock bin file I created earlier today, yet fastboot devices returns nothing and fastboot reboot returns &lt; waiting for devices &gt;.

Is there anything I can do short of using a USB-OTG cable to sideload a custom ROM?

I would be inconceivably grateful for any help which gets me closer to getting my phone working again. Thanks in advance!



EDIT 1: So, after rebooting a couple of times, *** Security Warning *** is no longer there and fastboot devices now returns my serial number. However, adb devices still returns nothing. Any idea what's going on?
Woah! I'm not entirely sure what happened, but it suddenly started working again - I now have CM 11 up and running.

Here are some notes on what I was doing which will hopefully be helpful for someone else who has the same problems I did:


First off, I was running Windows 8 in a Parallels VM. I don't know if either Windows 8 or the VM was the culprit, but either way, it was silly and probably didn't help things. Getting ADB and FastBoot up and running in OS X seemed to make a difference.
Also, there is a chance that there were some problems with directory partitioning/formatting - it suddenly started working after I wiped the system a few times with TWRP (Wipe > Format Data) and rebooted. Obviously you'll lose everything, but better to lose a few files and get your phone back!


Other info that I found that wasn't relevant to me but might make a difference:


Apparently USB 3 can cause issues - try different USB ports, particularly USB 2 over USB 3.
Windows 8 may not play nice - try Windows 7 or XP (or Linux!)