Teensy 3.5 Failing

Greetings, Hope someone can help. I have a 32 x 64 matrix, SmartMatrix Shield and Teensy 3.5 which has the SD card reader. I’m running sequences of BMP pics and GIF animations some of which are up to 10 hours long. It’s been working great (Thanks to some help from Louis), except after several days to several weeks, the Teensy just dies. When I turn it on, no display and the 3.3V regulator and processor on the Teensy board are very hot. I’ve gone through about four Teensys and it’s getting old replacing them at about $30 each.
Has anyone else had this problem? Might it be the Shield board?
I have some other display sketches that don’t require the SD running on a Teensy 3.2. No failures (yet!)
I appreciate any help. Meanwhile. I tried connecting an external card reader to the 3.2 but so far, it won’t recognize it. Just to check myself, what pins should the external card use?

Hi Stan,

It’s really frustrating to lose a Teensy, let alone 4! I haven’t hard of this issue before.

What else do you have connected to your Teensy or shield? How are you powering it?

Just to check myself, what pins should the external card use?

Look at the pinout photo showing a micro SD card adapter with numbers on it here. It’s for a different shield, but the Teensy pin numbers are the same:

Thanks for the response, Louis. The Teensy pinout for the SD card is what I’m using so I may have a defective reader or other problem.
I’m using a 5V, 5A supply for the matrix and when working with code and such, running the Teensy from a laptop. However I also have the matrix supply jumpered through a switch so I can run both from that. Maybe putting a capacitor on the board will help with surges.
Thanks again.

Make sure you set the CS pin in the sketch to match what you’re using in the hardware

Can you describe how the main power supply is connected, and or send a picture? Maybe I can spot an issue.

Louis, here is a pic of the hookup. CS is pin 15 for the SD card reader. Oh BTW when using the 3.5, I also had a 4x20 LCD display connected for status info while doing matrix pics and videos. I disconnected it when I hooked up the card reader.

I can’t see the details of that circuit through the picture

Hi Louis, sorry about the pic. Here are a couple more. Incidentally, I unplugged the card reader (at left in the first pic) and tried it on an arduino with display. It worked fine.
Oh and the extra yellow wire on the little blue pcb was connected to the button, read by the T3.5 when showing a Gif to advance to the next one.

I think you should connect the ground from the panel’s power connector to the shield. True, there’s already a ground connection through the HUB75 connector, but if that comes loose then your only power connection between the panel and shield is VCC and no ground connection. I don’t fully follow what’s going on with the switch board, but the VCC without ground connection in parallel stands out as an issue.

That’s a good point, Louis. The switch board has a switch that provides Vcc from the Matrix power to the Teensy through the LED Strip connector. It also has a button with a pull-down resistor to tell the Teensy and sketch to jump to the next video.
I’ll add a ground from Matirx power to the shield. I think I’ll also add a capacitor across Vcc and Gnd at the shield or Teensy to guard against spikes.
Thanks again for your help.

Update: FYI, I added the ground wire you suggested and a capacitor across the power at the Teensy. So far no failures. Seems to be working just fine. And I can leave it running all day with many hours of gif files running in sequence. Thanks again for the help!

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