3uTools sometimes uses modified drivers. To rule that out:
However, if the baseband hardware is truly dead, the device will never have cellular functionality again, but can still be used as an iPod touch / WiFi device (except iPhone 7 models with known audio IC + baseband combo failure – those may bootloop). 3utools error unable to restore idevice--75-
This error typically appears mid-way through a restore or firmware flash, leaving your device stuck in Recovery Mode, DFU Mode, or with a black screen. But what does error -75 mean, and—most importantly—how do you fix it? 3uTools sometimes uses modified drivers
Some advanced users have fixed error -75 by swapping ports at the exact moment the baseband begins flashing. But what does error -75 mean, and—most importantly—how
If a standard "Easy Flash" fails, putting the device into DFU (Device Firmware Update) Mode is often the silver bullet. This bypasses the OS entirely and forces the device to accept the new firmware.
The is intimidating, but it is rarely a death sentence for your iDevice. By methodically working through this guide—starting with DFU mode, moving to manual IPSW installation, and finally checking hardware—you have an excellent chance of recovery.