Hi all, so I received my teensy 3.2 the other day and successfully uploaded aurora hex file. I then decided to upload the aurora.ino sketch via arduino IDE instead which again I did without problems. I then received my smartmatrix sd shield v3 and soldered it up following instructions exactly. Cut trace, diode correct way round and all solder joints good with none missed. ( soldered teensy to shield and not female headers, which I now regret!) I applied power to the shield and connected USB and now I can’t upload anything to the teensy. When the teensy loader pops up the upload and reboot buttons are greyed out and are not clickable and pressing the reset button on teensy does nothing either. Have used a meter on 5v and gnd pin of shield which gives me a reading so fairly sure the shield is ok and when I put meter on vin and ground of the teensy there’s power going to the teensy but no lights and teensy is totally unresponsive. Port not recognised when plugged into arduino IDE and computer makes no sound when I plug teensy and shield in like it should when any USB device is plugged in so fairly sure I have fried the teensy somehow 
have soldered a million times before so fairly sure it’s not my soldering, any ideas as to what I could have done to cause this??!! I will be attempting again but now scared this is going to happen again! Am I right in saying that with the trace cut on teensy, I need both USB and power to the shield in order to upload a sketch? (I did try with and without power) also, if I don’t cut trace on next teensy, I will need to connect both USB and power to shield in order to make the matrix work? (I know about risk of power going to computer, just curious) many thanks for any help
Port not recognised when plugged into arduino IDE and computer makes no sound when I plug teensy and shield in like it should when any USB device is plugged in so fairly sure I have fried the teensy somehow
There’s one thing I’ve done to revive an unresponsive Teensy: hold down the program button as you connect to USB. I think that triggers the bootloader chip to do something special to revive the main microcontroller, but I don’t recall the details.
Correct
also, if I don’t cut trace on next teensy, I will need to connect both USB and power to shield in order to make the matrix work?
In that case, you can probably just apply USB power to program the sketch. There is a chance that if there are a lot of LEDs driven by the panel while you’re programming, it could draw too much current from USB and cause a problem, but this is unlikely.
Feel free to post some pictures of the non-working shield and I can look for any issues. Front and back would be best