Help with Nokia Lumia 635 RM-974 - Urgent!

I have a Nokia Lumia 635 (model RM-974). Unfortunately, it won't boot up correctly. Every time I try to turn it on, the Nokia logo appears, followed by a BSOD. When I connect it to my PC, it consistently shows up in Device Manager as an "Unknown USB Device (Device Descriptor Request Failed)." The phone's buttons work perfectly, but even when I try to enter a specific mode, the phone just displays the Nokia logo and restarts—it just keeps doing that. The only mode I can still access is the one triggered by holding Volume Up + Power (the one showing the lightning bolt and gear icons), but even in this mode, the PC recognizes it the same way. I have tried using different PCs and cables and installing various drivers, but that isn't the problem. Unfortunately, since the PC doesn't recognize the USB-connected device, tools like WDRT, thor2, or WPInternals can't detect it either. I look forward to hearing from you soon.