[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] bionemesis:
I'd like to share with you all my tale of rom flashing gone horribly wrong. It's really only important for 2 pieces of misinformation that I've seen kicking around the forums. First, the story.

I had already rooted my Telus Galaxy S3 (SGH-i747M), but was still running stock. I started looking around for compatible roms running JB, but didn't have much luck (finding ones that support the Canadian version is not easy). At the same time, I had to update and reset my old Galaxy S2 for a relative who was taking it off my hands. I found a JB rom that was available for both the S2 and S3, from the same dev. I decided to try both out, downloaded them and copied the respective files to the S2 and S3, but quickly realized that the S3 version didn't support my Canadian phone. No problem, I'll leave the S3 as rooted stock.

I proceeded to flash and install the rom on my S2. Everything seemed to be going fine until the first reboot after flashing. The phone appeared to be completely dead. I tried putting the phone into download mode but it was completely dead and would not even show signs that it was plugged into a power outlet. Then, horror. Both my S2 and S3 are in Otterbox Commuter cases. They look very similar. At 1 in the morning in a dimly lit room, they look identical.

Yes. Like an idiot, I had installed the incompatible S3 rom to my Canadian S3. I had, in fact, hard bricked my phone. I set aside my grief for 10 minutes and got the S2 done, as that was the original goal of this adventure. That worked fine. Of course.

For the next several hours and most of the following day, I searched and searched. I ended up on the posts talking about QHSUSB_DLOAD and how I'd screwed myself. No hope. Only option is either JTAG service or, and this brings me to misinformation #1, sending it back to Samsung. Why send a rooted and screwed phone back to Samsung? Well, the argument was that in all likeliness they wouldn't be able to tell and would probably just get it up and running anyway, perhaps with some nominal fee. Also, and here comes misinformation #2, there was a good chance that they would have to fix the problem in order to verify it.

Thankfully, in my only intelligent move in the last year, I had opted to choose the extra device protection offered by my carrier. Which meant, if it wasn't covered under warranty, I could get a brand new phone at a significantly reduced rate. But it did mean I had to send it in to Samsung first. And so, I walked into a carrier store and simply stated that it wouldn't power up. I neglected to mention the whole "I'm an idiot and accidentally installed an incompatible rom at 1AM". At the end of the day, they don't care anyway.

So I waited for almost 3 weeks before getting an update from my carrier. Samsung had looked at it and had a quote. I called the store to find out the cost. The phone needs a new mainboard. $350+ (I remember it being more than $350 but less than $400). Ah, no thank you. I politely declined and contacted the company providing the device protection. No problem, phone would be in my hands in 2-3 business days. I just need to send the damaged phone back when I get it from Samsung.

When the phone did get back from Samsung (within 24 hours, I might add), it came with a note to the carrier indicating that the phone had been rooted. The store manager actually made a good point too. If they were able to get it up and running to figure out it was rooted, why did it need a new mainboard? In all likeliness, they just wanted to teach me a $350+ lesson in voiding the warranty. So, what did I learn from this experience?

1) If you are rooting multiple phones, don't leave them all laying around in identical cases in a dimly lit room at 1AM.

2) Don't root phones in a dimly lit room at 1AM.

3) If you royally mess up your bootloader and it won't boot up, Samsung can still boot up that phone.

4) If that same phone is rooted, Samsung can not only tell, but ensure that the phone remains in it's screwed state for return.

5) They might just try and teach you a $350+ lesson; my guess is this ultimately depends on who looks at it (just like walking into an Apple store and walking out with a replacement, prior to Applecare+).

If anyone is curious why I didn't JTAG service the phone, it's simply because I can't afford to wait that long without a phone and the cost difference between JTAG and my device protection plan is not significant.