Raspberry Pi 3B Boot Loop Issue

System Details: Model: Raspberry Pi 3B Operating Systems Tried: Raspberry Pi Lite & Full OS (Official Raspberry Pi OS images) SD Card: 128GB microSD (integrity verified) Power Supply: Official 5V supply (used previously without issues) Symptoms: Pi hangs at the “done.” message and then restarts after about 10 seconds. RGB display shows rapid, alternating green and red flashes. Boot log shows USB device events (e.g., “new high-speed USB device found”) even when no USB peripherals are attached. Issue occurs regardless of attached peripherals (ethernet, keyboard, or none). Recent Changes: WiFi configuration updated via raspi‑config. WiFi Country Code: Set to “UK” (should be “GB” for the United Kingdom). Boot loop began after making this configuration change. Troubleshooting Steps Already Taken: Tried multiple OS images and repeatedly wiped/reflashed the SD card. Tested with different peripheral setups (with and without ethernet/keyboard/display). Verified SD card integrity and power supply consistency. No explicit error messages besides the continuous reboot loop. Current issue: The Pi won’t fully boot, preventing access to raspi‑config to correct the WiFi country code. Need guidance on modifying the configuration offline or other workarounds to resolve the boot loop.

i do apologise for the low quality but this was the best i could get

if anyone could @ me for any questions or solutions that would be hugely appreciated. im going to go to sleep because i have not caught any sleep over this <:cartired:984435344307027978>

just for the final piece of information, everything was working perfectly until one moment. and I do not know how to diagnose what broke, im starting to think its hardware but i have no clue how to tell