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View Full Version : Bad batch of Teensy 3.0?



pHysiX
12-27-2013, 07:47 AM
Hi fellow Teensy devs!

Special shout-out to Paul and Robin for a great product. :o

Im here to share about programming and/or use (connection) problems with the Teensy 3.0.

Summary:
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Poor solder joint on the IC just under the USB connector (Mini54tan???).


Story:
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For me, I got my first Teensy 3.0 a few days ago.

Connecting it to a Windows machine (32bit and 64bit), I noticed the Teensy kept connecting and disconnecting. Looking in device manager, I could not find it as a HID device. There was one point where the pre-loaded blink worked for a few minutes then never again.

I tried to reprogram the Teensy, but kept getting the "Reset" message. Pushing the push button did not work. I tried to hold the button, disconnect and reconnect. I used 4 different micro USB cables too.

On my Mac, the same programming issue was present, and the blink program did not work. However, the Teensy was seen as an HID device.

So what I did was I re-soldered/reflowed the Cortex M4 chip: No use.

Then I checked the schematic and found that the push button was connected to another controller, a tiny square chip just at the USB connector. An inspection under my loupe showed some poor solder joints :(

After 5 minutes (re-solder and flow), the Teensy is now rock solid!!! ;) I can disconnect, reconnect, program, on Windows I can use the button to program, on my Mac everything is working ultra smoothly!


Outcome:
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So for all folks having weird programming issues where pushing the button just doesn't seem to work, or if your Teensy just appears dead, perhaps there is a bad solder joint on one of the two ICs. This can definitely prevent the Halfkay bootloader from correctly communicating with the programmer, or it could cause unexpected behaviour preventing the Teensy from being a serial device if enabled under Tools->USB Type.


I hope my finding could help improve QC, because it has been a frustrating 3 days trying to figure out why nothing in my home would want to be friends with my Teensy :p

Ian