The first time she plugged it in and went to bed. All was well with it when it was plugged in. Woke up and nothing worked. No charging lights, nothing. Sent it in for warranty repair and T-Mobile/HTC said that the LCD screen was broke and that it was due to user damage (basically trying to say the phone was dropped, which it wasn't). They sent out a new phone, we sent back the broken one. A week later they charged our bill for the repairs and I had to call in 3 times in order to get them to finally waive those charges.
Now, a few months later, this new phone does the same thing. In the middle of using it, while it had plenty of battery, the screen went black. Same exact thing, would not power back on. Now we are in the process of waiting for the next phone to be shipped so we can ship this one back. And I'm fairly certain that they're going to try and use the same excuse again.
The only response that we get from the phone is when it is plugged into a computer and it asks to install the QHSUSB_DLOAD driver (which does nothing upon trying to install). After searching these forums, and Google, I noticed that everyone with this exact problem was trying to install a custom ROM. That is not the case with us. The OS on the phone's were never altered. The phone's were never unlocked. Nothing like that at all.
I don't really have a question that I'm asking here. From what I've read, it looks like the phone is basically bricked and there's nothing that can fix it. I just wanted to make this post so others know that this can happen to non-rooted phones too.
I'll follow up here once T-Moble/HTC give me the outcome of this second phone.