teensy3.6 dead on arrival?

[kho]

Hi,

My Teensy3.6 arrived in the mail today and I thought I gave it a spin.
Unfortunately the led is not blinking when I connect the Teensy to my PC. I have not uploaded a sketch before.
I double checked the following:
- the usb cable is fine, I used the same cable to connect to an Arduino Due and my PC detected it right away
- I'm using Linux as a development environment. I'm not seeing the Teensy being enumerated at all, I'm using lsusb to test this. I plugged/unplugged several times, I also waited a bit after connecting.
- I hooked up a scope to the 3.3V pins, the scope is measuring correctly 3.3 V.

The only explanation I could think of is that I fried the board while soldering the header pins.
Then again I used a professional soldering station, didn't put the temperature to high...

Any ideas what do next? Ship it back?

Many thanks in advance,
Klaas.

 

[PaulStoffregen]

Maybe Program or Reset got accidentally shorted to ground? Trouble on either of those would keep the board from running the LED blink, which is should still have in memory if no upload has ever happened.

Sounds like the board wasn't used or tested *before* soldering?

 

[Theremingenieur]

1.) You should perhaps have tested it before soldering the header pins
2.) You say that you use linux. Did you install the needed udev rules for the Teensy, so that the USB can be enumerated? That's a thing which the Arduinos with an external serial-to-usb converter IC don't need...
3.) A differential diagnose on a Windows PC or a Mac could be helpful to see if it's a linux or a Teensy problem
4.) You never should (as for all electronic components) order only one piece to allow to identify individual problems. If you had ordered the usual batch of 3 Teensys, diagnostic would be easier now.

 

[kho]

In the mean time I retried on Mac and I also removed the Teensy from the protoboard to rule out accidental shorts on any of the pins. But no luck either.
So I guess the Teensy is damaged, probably by the soldering and/or ESD.

Anyway, thanks for the help guys.

btw: the udev rule seems to reserve ttyACM* for the Teensy, probably required by Arduino-software.
But I don't think it has anything to do with the USB enumeration itself, this is handled by the kernel.

 

[PaulStoffregen]

The first step with a new Teensy is always to look at the LED. During testing, every Teensy gets programmed through the USB with the LED blink program. If the board is working, every brand new Teensy should blink its LED. No USB communication is needed. Even when using a charge-only cable that lacks data wires, the LED blinks.

The second step is to press the button. The LED blinking should stop, because pressing the button puts Teensy into bootloader mode.

Of course, a previously used Teensy will almost certainly have a different program in its memory. This only applies to brand new boards. They always have the LED blink loaded when they are brand new.

On the USB stuff, with Linux you can run "tail -f /var/log/syslog" to watch messages from the kernel. The kernel will give these messages regardless of udev rules. When Teensy goes into bootloader mode, the kernel should see a HID device with ID 16c0:0478. Teensy is NOT a serial device when shipped, or in bootloader mode, so looking for /dev/ttyACM devices is not the correct way to troubleshoot.

Troubleshooting should be done by running Teensy Loader. If the udev rule is installed, it should automatically detect when the HID device appears.

The udev rule file does not "reserve ttyACM* for the Teensy". Much info exists online about how udev rules work. But all this worry about udev rules and especially serial devices is the last step for troubleshooting. Start at the beginning, with looking at the LED (if Teensy is still brand new) and test with Teensy Loader which looks for the HID device with ID 16c0:0478.

MANY people have incorrectly diagnosed their problems by looking only for serial devices, believing Teensy to be dead, when in fact it was working exactly as it should with HID protocol.