nRF5340-DK no longer detected by USB after months of normal operation

Question

Hi, 
 My nRF5340-DK (serial number 001050065828) suddenly stopped being detected by USB on Windows 11 after months of normal operation. I did not change anything in the hardware setup between the last successful flash and the failure. 
 Symptoms: 
 
 LED 3 blinks on the DK → the nRF5340 application core appears to still be running 
 LED 1 and LED 5 are off → no USB/JLink connection established 
 nrfutil device list returns no nRF5340-DK, only an unrelated FT232R device 
 west flash --snr 001050065828 returns: "No devices with requested serial number(s) or trait(s) found" 
 Device Manager shows no J-Link or SEGGER device when the DK is connected 
 A second nRF5340-DK works perfectly on the same computer and USB cable 
 
 What I tried: 
 
 Different USB cables 
 Different USB ports 
 Unplugging all external connections (breadboard, GPIOs) before connecting 
 west flash --recover 
 nrfutil device list on multiple attempts 
 Pressing RESET while reconnecting USB 
 
 Environment: 
 
 OS: Windows 11 
 nRF Connect SDK: v3.2.1 
 west: 1.4.0 
 nrfutil: latest 
 Board: nRF5340-DK (PCA10095) 
 
 Question: Is the JLink interface chip on the DK dead? Is there any way to recover it without external programmer hardware? Could a firmware corruption on the interface chip cause this, and if so, how can it be reflashed? 
 Thank you