Teensy LC will not program

Hi
I have several LC's and all but the newest work perfectly. Let me call a good one LC1 and the problem unit LC2. I have read your notes on Bricked Teensy, Troble shooting... I am running teensydunio in Linux Mint. I remove my teensy from the target board for programming. When I plug it back in, it drives an LCD display, responds to a keypad and drives a stepper motor.

But I cannot reprogram LC2. I programmed it at least once and the program in it works in the target, drives the display and responds to the keypad. But I cannot update it. If i plug in LC1 to the USB, it programs and runs normally so my code, drivers, and cable must be ok. (I also tried a third unit and it programs correctly). The serial port outputs properly for LC1 and LC2. But I cannot reprogram LC2. I tried the button while connected and while I plugged the USB cable all to no avail.

Then I read about the 15 reset. I did that and it must have reset because it no longer works in the target system. But I still cannot program it. Do I have to do something special after the 15 second reset?

Or is it toast?

Dave

I'm not sure the 15 second reset exists beyond the T_3.5/3.6.

Try a simple blink like the one posted here with other tips.

You have a good cable it seems - load this sketch in the IDE and push it to LC1 - see it work. Then swap in the LC2 to same USB cable while holding the button - wait a sec - release the button. That should excite the TeensyLoader to action I think - if not hit Verify in the IDE and then press the button. Blinking sketch working?