2025-07-03 6:53 AM
Hello all,
I've been using my STLINK V3 successfully for around half a year until it suddenly stopped working from one day to the next. When connecting it to the PC (no target) the green light is on and the red light if flashing forever. It does not turn orange like described in the manual, neither switch to constant red, as it was before. Windows it not recognizing it as an USB device at all (the first two times it showed something like unknown device, but never again since).
My setup works with another STLINK V3 so I would exclude cable, USB port issues or similar.
Any idea, what the issue here is, or how to fix it?
2025-07-03 7:03 AM
If red light is flashing, it indicates the chip is trying to connect but enumeration is failing. Typically this is due to a bad cable, perhaps a power-only cable. It could also be that your PC doesn't like that device for some USB stack reason. Rebooting can sometimes fix this.
2025-07-03 7:13 AM
FAQ: Possible communication failure between STLINK-V3 and some recent computers
2025-07-03 9:10 AM
I tried already several cables ans USB ports, even another PC, but the behavior is the same. As mentioned above on the same PC, same USB port, same cable my ST Links used to work and another ST link is still working perfectly. That's why I concluded, that something with the actual STLink HW must be wrong.
2025-07-04 12:43 AM
I connected the STLink to a Linux PC and got the following log. I hope this helps to determine the issue.
[ 99.227313] usb 1-2: new full-speed USB device number 5 using xhci_hcd
[ 99.342252] usb 1-2: device descriptor read/64, error -71
[ 99.563204] usb 1-2: device descriptor read/64, error -71
[ 99.786283] usb 1-2: new full-speed USB device number 6 using xhci_hcd
[ 99.901289] usb 1-2: device descriptor read/64, error -71
[ 100.123345] usb 1-2: device descriptor read/64, error -71
[ 100.232439] usb usb1-port2: attempt power cycle
[ 100.612313] usb 1-2: new full-speed USB device number 7 using xhci_hcd
[ 100.612520] usb 1-2: Device not responding to setup address.
[ 100.816448] usb 1-2: Device not responding to setup address.
[ 101.024232] usb 1-2: device not accepting address 7, error -71
[ 101.024327] usb 1-2: WARN: invalid context state for evaluate context command.
[ 101.138232] usb 1-2: new full-speed USB device number 8 using xhci_hcd
[ 101.138438] usb 1-2: Device not responding to setup address.
[ 101.344489] usb 1-2: Device not responding to setup address.
[ 101.552070] usb 1-2: device not accepting address 8, error -71
[ 101.552168] usb 1-2: WARN: invalid context state for evaluate context command.
[ 101.552279] usb usb1-port2: unable to enumerate USB device
2025-07-04 1:22 AM
So you have a bad contact on one USB data line - or you killed this V3 (maybe static discharge, the "usual way").
2025-07-21 2:46 AM
Hi @phil_spobu
Given the symptoms and error logs, the USB interface hardware in the STLINK V3 is probably faulty.
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