| Symptom | Likely Cause | |---------|---------------| | Cable not detected in Device Manager | Missing driver or dead hardware | | Yellow exclamation mark on “Prolific USB-to-Serial Comm Port” | Driver conflict or counterfeit chip | | Error Code 10 (This device cannot start) | Incompatible/inf driver | | Error Code 43 (USB device not recognized) | Chipset malfunction or driver crash | | COM port appears but cannot open in PuTTY/SecureCRT | Driver not fully initializing or port busy | | Works on Windows 7 but not Windows 10/11 | Microsoft driver enforcement or driver deprecation |
If you see any of these, proceed with the fix steps below. You cannot fix the driver without knowing the exact chip. Here’s how:
Yes, for Cisco gear, you need a rollover (not straight) cable. But the AWM 20251 console cable is usually wired as rollover internally. Check continuity.