Problem with Teensy 4.1 and Teensy 4.1 NE from Sparkfun

[skpang]

I have a batch of 9x Teensy 4.1 and 18x Teensy 4.1 NE from Sparkfun.

When I plug the USB cable in, the orange LED does not flash and no comm port appears on the PC.

I tried to press and hold the prog. button for 15 seconds. The red LED flash once and when I release the button the red LED stays on.
I power cycle the board but still no flashing orange LED and no comm port.

I've tried different USB cable and on different machines.

Is there anyway to recover this ?

The T4.1 has a date code of CTRZ2516E
T4.1 NE has a date code of CTUA2525E

 

[PaulStoffregen]

The red LED flash once and when I release the button the red LED stays on.

How long did you wait? The flash erase is very slow, more than 1 minute on Teensy 4.1.

Eventually it should complete and the board reboots. Red LED should turn off and orange LED should blink slow.

 

[skpang]

I waiting for about 20 seconds until the red LED flash once.

I think I solved the issue. I have to have the Arduino IDE and the Teensy programming app running. Compile the blink sketch, press the prog. button once it will progam the new blink sketch and all is well. If I just try to upload the sketch it says no teensy were found and ask me to press the prog. button.

I've programmed thousands of Teensys before and first time plug in the USB cable the orange LED always flashes but not this new batch.
Something has changed and I'm sure its not my process.

 

[kd5rxt-mark]

@skpang: @PaulStoffregen is not asking how long you waited while pressing the button (which you identified as "about 20 seconds"), he's asking specifically about how long you waited after releasing the button. It seems that you're starting the factory reset process correctly (you hold the button until the red LED flashes once, then release the button), but are you waiting long enough for the process to complete (potentially several minutes) ??

See <this> post for a detailed description of the entire factory reset process & make sure that you are following it in every way.

Hope that helps . . .

Mark J Culross
KD5RXT