We have experienced ongoing failures of Teensy 4.1 modules in our system over the last 18 months. These failures appear random and arbitrary except:
1) Never fails during normal operation. In other words once up and running fine during that power cycle.
2) The symptom of the failure is that the 3.3V rail on the Teensy is shorted to ground. We have removed the 3.3V regulator the the rail remains shorted.
3) It is our strong impression that these failures only happen when a USB cable is connected/disconnected, Note we often, but not always connect USB cables with the USB 5V power disconnected.
4) We have placed diodes from the 3.3V line to the 5V rail as per some of the posts here to ensure that we are not backfeeding the 5V rail through the 3.3V. This did not help.
We have never had this type of problem with the 3.2 Teensy. This is becoming a critical problem for us as we need USB access to the our system via the Teensy but at this point we risk system failure every time we plug in the USB cable.
Any thoughts or what we can check on the Teensy 4.1 to further try and diagnose this issue?
1) Never fails during normal operation. In other words once up and running fine during that power cycle.
2) The symptom of the failure is that the 3.3V rail on the Teensy is shorted to ground. We have removed the 3.3V regulator the the rail remains shorted.
3) It is our strong impression that these failures only happen when a USB cable is connected/disconnected, Note we often, but not always connect USB cables with the USB 5V power disconnected.
4) We have placed diodes from the 3.3V line to the 5V rail as per some of the posts here to ensure that we are not backfeeding the 5V rail through the 3.3V. This did not help.
We have never had this type of problem with the 3.2 Teensy. This is becoming a critical problem for us as we need USB access to the our system via the Teensy but at this point we risk system failure every time we plug in the USB cable.
Any thoughts or what we can check on the Teensy 4.1 to further try and diagnose this issue?