[HTC EVO 3D] WatermelonSlim:
I am not sure if you're being serious here or just trolling. I'll play along.

Your warranty is void as soon as you root your phone. Period. There is no HTC warranty and a separate Sprint warranty. You have one warranty, from HTC. Sprint tries to repair devices and will even swap your phone out for you in some cases, but they are then sending them back to HTC. They deal with them for you in the name of customer service (and as a selling point for their insurance/replacement/repair plan).

The warranty being void when you root isn't dependent on why the phone bricks, or even if the phone bricks. If you root your phone, you void your warranty. Period. They are no longer obligated to replace it if you brick it, no matter what caused it to brick.

And yes, I know Sprint usually replaces it anyway. That only proves my point that they are not at all worried about it getting too expensive. If they were, they would stop replacing bricked phones that they know darn well they don't have to. At the very least they would be checking with HTC to see if there is a record of you voiding your warranty.

And another thing... Just because your phone is bricked doesn't mean HTC can't put it on a machine and have it fixed and back to stock in less than a minute at a cost of only a few bucks in labor. Just because YOU can't fix it doesn't mean it will forever be a brick. If it's just a firmware issue, it can be fixed quickly, cheaply, and easily. WE can't do it because we don't have the proper equipment. HTC does.

And lastly, why the heck do you keep saying to flash an Evo 4G radio on my Evo 3D? I would only flash a radio that was meant for my phone. But for the record, almost every single "good" radio for the Evo 4G (and every phone before it) was taken from another device, and then modified to work on the Evo 4G. I have flashed more of them than I can count over the years, and never once bricked a device. We don't see this on the Evo 3D because, well, it's locked down so there is not much development for it.

And even if it was such a huge risk of bricking like you say (which it's not) it still shouldn't be any of HTC or Sprint's concern what I do with my phone. If I brick it, my warranty is void anyway so don't replace it. I'll pay the insurance deductible, they'll swap it out, and everyone is happy. And the insurance will probably just send it to HTC and pay them to refurb it anyway. Which will take HTC all of 5 minutes to do, at a cost of only a few dollars. But they'll charge the insurance company $20 to $50 so they'll make money off that too. I pay the insurance company every month, plus the high deductible, so they are still making money even if they have to send it in for a refurb. Everyone's happy.

Nobody is "losing" money replacing bricked phones like you claim. That had nothing to do with this. But when Sprint caps 4G speed at 4-6 megs, and Evo 4G owners are flashing modified radios and pulling 8-12 meg downloads (and I was one of them so don't try to tell me this didn't happen) then Sprint probably wants to curb that.

EDIT:

Check this out:

http://forum.ppcgeeks.com/showthread.php?t=127525

Someone better tell him that flashing radios is so dangerous. Seriously, in the 193 pages for that ROM I bet there is not 1 single person who bricked their phone flashing that. And it has a radio, plus another Wimax radio.