[AT&T, Rogers HTC One X, Telstra One XL] phi11yphan:
I managed to permanently brick 2 ATT HOX in as many weeks. My bad. When i say brick, i don't think i mean recoverable. I effectively killed the phone's ability to power up, period. Hoping someone here can prove me wrong. (Ex: maybe by jumping a combination of the 5 metal dots on the back of the HTC One X will force it to try reinitializing?)

Symptom: phone will not power on. Holding down the power button for 10 minutes results in the same (dead?) black screen, with no signs of any backlight, power light, nothing.

Before brick: Full battery (93%), was working fine as ATT ICS 4.0, before i tampered with it. Was on version 2.20.(520 or 502) before i killed it. Came stock, which i didn't like, so i chose juicy-looking ICJ v3.4 rom, with plans to add gApps, su. Trying to remember steps to recreate:

tried rooting phone using promising one click root, but got a bunch of permission denied, adb out of date errors. Killed existing adb processes, HTC uploader, etc -- but to no avail. So i gave up after a few tries

bootloader was locked, so i figured to unlock it and flash a rom afterwards. Tried HTC Dev but failed on "unauthorized" error.

used x factor root to successfully unlock bootloader while also changing CID to all 1's. At this point, i think i created the "tampered" mark in bootloader. Oh well.

flashed awesome Team Win Recovery Project twrp v2.3.1 to success

in twrp: fixed permissions, cleared cache, dalvik cache, system... and finally made the infamous (dumb) mistake of flashing external storage and losing the ZIPs i had already placed on the sdcard. Now had no way to install a new OS; and had already deleted my existing OS.

tried to use ADB push to place the zips back on sdcard.... but failed on "unable to mount sdcard" error.

used awesome tutorial by xsmagical to rebuild corrupt partitions, to be able to adb push to a mounted sdcard again

once sdcard was mounted again, pushed ICJ, gapps, and su 0.98 to sdcard

in twrp, installed ICJ successfully from zip. I should be golden at this point, right???

nope. reboot system... to never wake ever again. Never see a boot screen to ever witness ICJ.

press power for 30 seconds.... nothing, Try for 5 minutes... nothing. 10 minutes.... nothing. USB cable connected, disconnected.... power cord connected, disconnected..... nothing.

waited a full week for the power to die -- in case all the phone needed was time to shut down completely. then charged for a full night, tried again in the morning.... nothing.

tucked tail between legs, took bricked phone to ATT device support center, made best innocent-face "dunno what happened", got replacement.

repeat, like an idiot

If i could change anything, i certainly wouldn't use all those tasty (possibly unnecessary) options in twrp to clear the system/caches prior to flashing a new rom.

So, I have another HTC One X to take back to the ATT device support center. They will surely look at me funny the 2nd time around. (The first time we decided to say the power button was stuck. LOL) At least they can't even power the unit to ever see the "TAMPERED" mark in at the top of the bootloader.

If i get another HOX from them, I will surely deviate from the steps above. Hopefully someone reading this thread can figure out a way i can avoid making that shameful visit to claim a 2nd replacement device in as many as 3 days. Any ideas? Did i miss something? Could the phone be on, but unable to turn on the display?

Otherwise... any suggestions to flash ICJ but avoid a 3rd brick are also welcomed.