Is my Teensy 3.2 fried?

I've been doing some tests using a Teensy 3.2 and OctoWS2811 to drive LEDs. I had the combined boards sitting on top of a 5V power supply (Meanwell NES-100-5) and it worked fine like this for a long time. Then I unplugged the power supply and replugged it and the Teensy stopped working correctly. When it was plugged in the /dev/ttyACM0 device was not present and there was no way to communicate with it. However, I found that after unplugging it, leaving it alone for a couple hours and plugging it in again, /dev/ttyACM0 would appear again once it was plugged in and the Teensy would appear in lsusb, but only for a few minutes. After being plugged in for 3-4 minutes, /dev/ttyACM0 was gone again. I tried unplugging and replugging it again and /dev/ttyACM0 reappeared, but this time it lasted for less than a minute before disappearing.

Apparently, the board now needs to have a period of downtime before the USB serial interface becomes available again. It's as if some charge has built up within the board that prevents /dev/ttyACM0 from working, and it dissipates when the board is unplugged but rapidly builds up again once it's plugged in. The USB communication with the Arduino IDE is still working, I can press the button on the Teensy and I see feedback in the IDE's console log. If this is electrical damage to the board, it seems to have strangely specific effects. Has anyone heard of anything like this before? I would think that if the board got hit by an electric discharge it just wouldn't work at all. Could something else be the cause?

I've attached the console logs of two times I pressed the button. At first you can see the "address" : "/dev/ttyACM0" property but it's gone after the first restart of the board, replaced by "usb1/1-1." Thanks for any advice.

First button press:
Code:
2025-03-22T18:54:38.378Z discovery-log INFO {"eventType":"remove","port":{"matchingBoardsList":[],"port":{"address":"/dev/ttyACM0","label":"","protocol":"serial","protocolLabel":"","propertiesMap":[],"hardwareId":""}},"error":""}
2025-03-22T18:54:38.386Z discovery-log INFO {"eventType":"remove","port":{"matchingBoardsList":[],"port":{"address":"usb1/1-1","label":"","protocol":"teensy","protocolLabel":"","propertiesMap":[],"hardwareId":""}},"error":""}
2025-03-22T18:54:39.402Z discovery-log INFO {"eventType":"add","port":{"matchingBoardsList":[{"name":"Teensy 3.2 / 3.1","fqbn":"teensy:avr:teensy31","isHidden":false}],"port":{"address":"usb1/1-1","label":"/dev/bus/usb/001/096 Bootloader","protocol":"teensy","protocolLabel":"Teensy Ports","propertiesMap":[["modelID","0x21"],["name","Teensy 3.2"]],"hardwareId":""}},"error":""}
2025-03-22T18:54:39.405Z discovery-log INFO {"eventType":"add","port":{"matchingBoardsList":[{"name":"Teensy 3.2 / 3.1","fqbn":"teensy:avr:teensy31","isHidden":false}],"port":{"address":"usb1/1-1","label":"/dev/bus/usb/001/096 Bootloader","protocol":"teensy","protocolLabel":"Teensy Ports","propertiesMap":[["modelID","0x21"],["name","Teensy 3.2"]],"hardwareId":""}},"error":""}
2025-03-22T18:54:39.406Z discovery-log INFO {"eventType":"add","port":{"matchingBoardsList":[{"name":"Teensy 3.2 / 3.1","fqbn":"teensy:avr:teensy31","isHidden":false}],"port":{"address":"usb1/1-1","label":"/dev/bus/usb/001/096 Bootloader","protocol":"teensy","protocolLabel":"Teensy Ports","propertiesMap":[["modelID","0x21"],["name","Teensy 3.2"]],"hardwareId":""}},"error":""}
2025-03-22T18:54:39.409Z discovery-log INFO {"eventType":"add","port":{"matchingBoardsList":[{"name":"Teensy 3.2 / 3.1","fqbn":"teensy:avr:teensy31","isHidden":false}],"port":{"address":"usb1/1-1","label":"/dev/bus/usb/001/096 Bootloader","protocol":"teensy","protocolLabel":"Teensy Ports","propertiesMap":[["modelID","0x21"],["name","Teensy 3.2"]],"hardwareId":""}},"error":""

Second button press:
Code:
2025-03-22T18:55:45.000Z discovery-log INFO {"eventType":"remove","port":{"matchingBoardsList":[],"port":{"address":"usb1/1-1","label":"","protocol":"teensy","protocolLabel":"","propertiesMap":[],"hardwareId":""}},"error":""}
2025-03-22T18:55:46.215Z discovery-log INFO {"eventType":"add","port":{"matchingBoardsList":[{"name":"Teensy 3.2 / 3.1","fqbn":"teensy:avr:teensy31","isHidden":false}],"port":{"address":"usb1/1-1","label":"/dev/bus/usb/001/097 Bootloader","protocol":"teensy","protocolLabel":"Teensy Ports","propertiesMap":[["modelID","0x21"],["name","Teensy 3.2"]],"hardwareId":""}},"error":""}
2025-03-22T18:55:46.218Z discovery-log INFO {"eventType":"add","port":{"matchingBoardsList":[{"name":"Teensy 3.2 / 3.1","fqbn":"teensy:avr:teensy31","isHidden":false}],"port":{"address":"usb1/1-1","label":"/dev/bus/usb/001/097 Bootloader","protocol":"teensy","protocolLabel":"Teensy Ports","propertiesMap":[["modelID","0x21"],["name","Teensy 3.2"]],"hardwareId":""}},"error":""}
2025-03-22T18:55:46.218Z discovery-log INFO {"eventType":"add","port":{"matchingBoardsList":[{"name":"Teensy 3.2 / 3.1","fqbn":"teensy:avr:teensy31","isHidden":false}],"port":{"address":"usb1/1-1","label":"/dev/bus/usb/001/097 Bootloader","protocol":"teensy","protocolLabel":"Teensy Ports","propertiesMap":[["modelID","0x21"],["name","Teensy 3.2"]],"hardwareId":""}},"error":""}
2025-03-22T18:55:46.221Z discovery-log INFO {"eventType":"add","port":{"matchingBoardsList":[{"name":"Teensy 3.2 / 3.1","fqbn":"teensy:avr:teensy31","isHidden":false}],"port":{"address":"usb1/1-1","label":"/dev/bus/usb/001/097 Bootloader","protocol":"teensy","protocolLabel":"Teensy Ports","propertiesMap":[["modelID","0x21"],["name","Teensy 3.2"]],"hardwareId":""}},"error":""}
 
I think it's much more likely to be heated related than a built up electrical charge. I think you've got a short somewhere. It heats up and eventually browns out, dropping the connection. Try disconnecting everything from the Teensy and powering up via USB. See if the connection drops out. If not then it's a problem with the other connected hardware.
 
If it's disconnecting, you should be able to see linux kernel messages with more specific info. On most linux distros run "tail -f /var/log/syslog" in a terminal.

Teensy uses HID protocol in bootloader mode, not serial. So you should *not* see a /dev/ttyACM device while in bootloader mode.
 
I appreciate the ideas, I don't think it's heat-related as there wasn't much heat in the workspace and the problem persists after the Teensy has been unplugged and set aside for over a day. Thanks for suggesting syslog Paul, I checked it and plugging in the Teensy creates a tidal wave of error messages:

Code:
Mar 24 20:37:30 myhost kernel: [5012059.816091] usb 8-4: new full-speed USB device number 20 using xhci_hcd
Mar 24 20:37:30 myhost kernel: [5012059.983412] usb 8-4: New USB device found, idVendor=16c0, idProduct=0483, bcdDevice= 2.75
Mar 24 20:37:30 myhost kernel: [5012059.983416] usb 8-4: New USB device strings: Mfr=1, Product=2, SerialNumber=3
Mar 24 20:37:30 myhost kernel: [5012059.983417] usb 8-4: Product: USB Serial
Mar 24 20:37:30 myhost kernel: [5012059.983419] usb 8-4: Manufacturer: Teensyduino
Mar 24 20:37:30 myhost kernel: [5012059.983420] usb 8-4: SerialNumber: 2482130
Mar 24 20:37:30 myhost kernel: [5012060.025499] cdc_acm 8-4:1.0: ttyACM2: USB ACM device
Mar 24 20:39:14 myhost kernel: [5012164.140505] usb 8-4: USB disconnect, device number 20
Mar 24 20:39:14 myhost kernel: [5012164.467355] usb 8-4: new full-speed USB device number 21 using xhci_hcd
Mar 24 20:39:15 myhost kernel: [5012165.643658] usb 8-4: device descriptor read/64, error -71
Mar 24 20:39:16 myhost kernel: [5012166.299366] usb 8-4: device descriptor read/64, error -71
Mar 24 20:39:17 myhost kernel: [5012167.159364] usb 8-4: new full-speed USB device number 22 using xhci_hcd
Mar 24 20:39:17 myhost kernel: [5012167.507371] usb 8-4: device descriptor read/64, error -71
Mar 24 20:39:18 myhost kernel: [5012168.375359] usb 8-4: device descriptor read/64, error -71
Mar 24 20:39:18 myhost kernel: [5012168.483386] usb usb8-port4: attempt power cycle
Mar 24 20:39:19 myhost kernel: [5012169.311343] usb 8-4: new full-speed USB device number 23 using xhci_hcd
Mar 24 20:39:19 myhost kernel: [5012169.311366] usb 8-4: Device not responding to setup address.
Mar 24 20:39:19 myhost kernel: [5012169.519375] usb 8-4: Device not responding to setup address.
Mar 24 20:39:20 myhost kernel: [5012169.727334] usb 8-4: device not accepting address 23, error -71
Mar 24 20:39:20 myhost kernel: [5012170.487318] usb 8-4: new full-speed USB device number 24 using xhci_hcd
Mar 24 20:39:20 myhost kernel: [5012170.487372] usb 8-4: Device not responding to setup address.
Mar 24 20:39:21 myhost kernel: [5012170.699328] usb 8-4: Device not responding to setup address.
Mar 24 20:39:21 myhost kernel: [5012170.911309] usb 8-4: device not accepting address 24, error -71
Mar 24 20:39:21 myhost kernel: [5012170.911363] usb usb8-port4: unable to enumerate USB device
Mar 24 20:39:21 myhost kernel: [5012171.191310] usb 8-4: new full-speed USB device number 25 using xhci_hcd
Mar 24 20:39:21 myhost kernel: [5012171.353455] usb 8-4: unable to read config index 0 descriptor/all
Mar 24 20:39:21 myhost kernel: [5012171.353461] usb 8-4: can't read configurations, error -71
Mar 24 20:39:22 myhost kernel: [5012171.699308] usb 8-4: new full-speed USB device number 26 using xhci_hcd
Mar 24 20:39:22 myhost kernel: [5012172.247340] usb 8-4: device descriptor read/64, error -71
Mar 24 20:39:23 myhost kernel: [5012172.907322] usb 8-4: device descriptor read/64, error -71
Mar 24 20:39:23 myhost kernel: [5012173.015367] usb usb8-port4: attempt power cycle
Mar 24 20:39:23 myhost kernel: [5012173.431296] usb 8-4: new full-speed USB device number 27 using xhci_hcd
Mar 24 20:39:23 myhost kernel: [5012173.468456] usb 8-4: unable to read config index 0 descriptor/all
Mar 24 20:39:23 myhost kernel: [5012173.468460] usb 8-4: can't read configurations, error -71
Mar 24 20:39:24 myhost kernel: [5012173.807292] usb 8-4: new full-speed USB device number 28 using xhci_hcd
Mar 24 20:39:24 myhost kernel: [5012173.807328] usb 8-4: Device not responding to setup address.
Mar 24 20:39:24 myhost kernel: [5012174.015336] usb 8-4: Device not responding to setup address.
Mar 24 20:39:24 myhost kernel: [5012174.223291] usb 8-4: device not accepting address 28, error -71
Mar 24 20:39:24 myhost kernel: [5012174.223363] usb usb8-port4: unable to enumerate USB device
Mar 24 20:39:24 myhost kernel: [5012174.503287] usb 8-4: new full-speed USB device number 29 using xhci_hcd
Mar 24 20:39:25 myhost kernel: [5012174.673456] usb 8-4: unable to read config index 0 descriptor/all
Mar 24 20:39:25 myhost kernel: [5012174.673461] usb 8-4: can't read configurations, error -71
Mar 24 20:39:25 myhost kernel: [5012175.011305] usb 8-4: new full-speed USB device number 30 using xhci_hcd
Mar 24 20:39:26 myhost kernel: [5012176.335304] usb usb8-port4: Cannot enable. Maybe the USB cable is bad?
Mar 24 20:39:26 myhost kernel: [5012176.335358] usb usb8-port4: attempt power cycle
Mar 24 20:39:27 myhost kernel: [5012177.183275] usb 8-4: new full-speed USB device number 31 using xhci_hcd
Mar 24 20:39:27 myhost kernel: [5012177.183300] usb 8-4: Device not responding to setup address.
Mar 24 20:39:27 myhost kernel: [5012177.395292] usb 8-4: Device not responding to setup address.
Mar 24 20:39:27 myhost kernel: [5012177.607269] usb 8-4: device not accepting address 31, error -71
Mar 24 20:39:28 myhost kernel: [5012178.363273] usb 8-4: new full-speed USB device number 32 using xhci_hcd
Mar 24 20:39:28 myhost kernel: [5012178.363336] usb 8-4: Device not responding to setup address.
Mar 24 20:39:28 myhost kernel: [5012178.571288] usb 8-4: Device not responding to setup address.
Mar 24 20:39:29 myhost kernel: [5012178.783256] usb 8-4: device not accepting address 32, error -71
Mar 24 20:39:29 myhost kernel: [5012178.783329] usb usb8-port4: unable to enumerate USB device
Mar 24 20:39:29 myhost kernel: [5012179.067262] usb 8-4: new full-speed USB device number 33 using xhci_hcd
Mar 24 20:39:29 myhost kernel: [5012179.229482] usb 8-4: unable to read config index 0 descriptor/all
Mar 24 20:39:29 myhost kernel: [5012179.229493] usb 8-4: can't read configurations, error -71
Mar 24 20:39:29 myhost kernel: [5012179.563276] usb 8-4: new full-speed USB device number 34 using xhci_hcd
Mar 24 20:39:31 myhost kernel: [5012180.739280] usb 8-4: device descriptor read/64, error -71
Mar 24 20:39:31 myhost kernel: [5012181.395275] usb 8-4: device descriptor read/64, error -71
Mar 24 20:39:38 myhost kernel: [5012188.487267] usb usb8-port4: attempt power cycle
Mar 24 20:39:39 myhost kernel: [5012188.899216] usb 8-4: new full-speed USB device number 43 using xhci_hcd
Mar 24 20:39:39 myhost kernel: [5012188.926491] usb 8-4: device descriptor read/8, error -71
Mar 24 20:39:39 myhost kernel: [5012189.058486] usb 8-4: device descriptor read/8, error -71
Mar 24 20:39:39 myhost kernel: [5012189.499207] usb 8-4: new full-speed USB device number 44 using xhci_hcd
Mar 24 20:39:39 myhost kernel: [5012189.536488] usb 8-4: unable to read config index 0 descriptor/all
Mar 24 20:39:39 myhost kernel: [5012189.536498] usb 8-4: can't read configurations, error -71
Mar 24 20:39:39 myhost kernel: [5012189.536571] usb usb8-port4: unable to enumerate USB device
Mar 24 20:39:40 myhost kernel: [5012189.847371] usb 8-4: new full-speed USB device number 45 using xhci_hcd
Mar 24 20:39:40 myhost kernel: [5012190.010489] usb 8-4: unable to read config index 0 descriptor/all
Mar 24 20:39:40 myhost kernel: [5012190.010499] usb 8-4: can't read configurations, error -71
Mar 24 20:39:40 myhost kernel: [5012190.343210] usb 8-4: new full-speed USB device number 46 using xhci_hcd
Mar 24 20:39:41 myhost kernel: [5012190.683211] usb 8-4: device descriptor read/64, error -71
Mar 24 20:39:41 myhost kernel: [5012191.139209] usb 8-4: device descriptor read/64, error -71
Mar 24 20:39:41 myhost kernel: [5012191.247237] usb usb8-port4: attempt power cycle
Mar 24 20:39:42 myhost kernel: [5012191.727190] usb 8-4: new full-speed USB device number 47 using xhci_hcd
Mar 24 20:39:42 myhost kernel: [5012191.727211] usb 8-4: Device not responding to setup address.
Mar 24 20:39:42 myhost kernel: [5012191.935210] usb 8-4: Device not responding to setup address.
Mar 24 20:39:42 myhost kernel: [5012192.143199] usb 8-4: device not accepting address 47, error -71
Mar 24 20:39:42 myhost kernel: [5012192.479183] usb 8-4: new full-speed USB device number 48 using xhci_hcd
Mar 24 20:39:42 myhost kernel: [5012192.511487] usb 8-4: device descriptor read/all, error -71
Mar 24 20:39:51 myhost kernel: [5012200.839183] usb usb8-port4: attempt power cycle
Mar 24 20:39:52 myhost kernel: [5012201.667124] usb 8-4: new full-speed USB device number 59 using xhci_hcd
Mar 24 20:39:52 myhost kernel: [5012201.698493] usb 8-4: device descriptor read/all, error -71
Mar 24 20:39:52 myhost kernel: [5012202.447114] usb 8-4: new full-speed USB device number 60 using xhci_hcd
Mar 24 20:39:52 myhost kernel: [5012202.478488] usb 8-4: device descriptor read/all, error -71
Mar 24 20:39:52 myhost kernel: [5012202.478549] usb usb8-port4: unable to enumerate USB device
Mar 24 20:39:53 myhost kernel: [5012203.071094] usb 8-4: new full-speed USB device number 61 using xhci_hcd
Mar 24 20:39:53 myhost kernel: [5012203.419099] usb 8-4: device descriptor read/64, error -71
Mar 24 20:39:54 myhost kernel: [5012204.075129] usb 8-4: device descriptor read/64, error -71
Mar 24 20:39:55 myhost kernel: [5012204.935106] usb 8-4: new full-speed USB device number 62 using xhci_hcd
Mar 24 20:39:55 myhost kernel: [5012205.279128] usb 8-4: device descriptor read/64, error -71
Mar 24 20:39:56 myhost kernel: [5012205.727128] usb 8-4: device descriptor read/64, error -71
Mar 24 20:39:56 myhost kernel: [5012205.835135] usb usb8-port4: attempt power cycle
Mar 24 20:39:56 myhost kernel: [5012206.315094] usb 8-4: new full-speed USB device number 63 using xhci_hcd
Mar 24 20:39:56 myhost kernel: [5012206.346496] usb 8-4: device descriptor read/all, error -71
Mar 24 20:39:57 myhost kernel: [5012207.303085] usb 8-4: new full-speed USB device number 64 using xhci_hcd
Mar 24 20:39:57 myhost kernel: [5012207.330497] usb 8-4: device descriptor read/8, error -71
Mar 24 20:39:57 myhost kernel: [5012207.462495] usb 8-4: device descriptor read/8, error -71
Mar 24 20:39:57 myhost kernel: [5012207.567127] usb usb8-port4: unable to enumerate USB device
Mar 24 20:39:58 myhost kernel: [5012208.363081] usb 8-4: new full-speed USB device number 65 using xhci_hcd
Mar 24 20:39:59 myhost kernel: [5012209.271091] usb usb8-port4: Cannot enable. Maybe the USB cable is bad?
Mar 24 20:40:00 myhost kernel: [5012210.239082] usb usb8-port4: Cannot enable. Maybe the USB cable is bad?
Mar 24 20:40:00 myhost kernel: [5012210.239137] usb usb8-port4: attempt power cycle
Mar 24 20:40:01 myhost kernel: [5012210.719061] usb 8-4: new full-speed USB device number 67 using xhci_hcd
Mar 24 20:40:01 myhost kernel: [5012210.746503] usb 8-4: device descriptor read/8, error -71
Mar 24 20:40:01 myhost kernel: [5012210.886475] usb 8-4: device descriptor read/8, error -71
Mar 24 20:40:01 myhost kernel: [5012211.331047] usb 8-4: new full-speed USB device number 68 using xhci_hcd
Mar 24 20:40:01 myhost kernel: [5012211.358500] usb 8-4: device descriptor read/8, error -71
Mar 24 20:40:01 myhost kernel: [5012211.490498] usb 8-4: device descriptor read/8, error -71
Mar 24 20:40:01 myhost kernel: [5012211.595135] usb usb8-port4: unable to enumerate USB device
Mar 24 20:40:02 myhost kernel: [5012211.903057] usb 8-4: new full-speed USB device number 69 using xhci_hcd
Mar 24 20:40:03 myhost kernel: [5012212.663066] usb 8-4: device descriptor read/64, error -71
Mar 24 20:40:03 myhost kernel: [5012213.111140] usb 8-4: device descriptor read/64, error -71
Mar 24 20:40:04 myhost kernel: [5012214.119032] usb usb8-port4: Cannot enable. Maybe the USB cable is bad?
Mar 24 20:40:04 myhost kernel: [5012214.119104] usb usb8-port4: attempt power cycle
Mar 24 20:40:05 myhost kernel: [5012214.947021] usb 8-4: new full-speed USB device number 71 using xhci_hcd
Mar 24 20:40:05 myhost kernel: [5012214.947047] usb 8-4: Device not responding to setup address.
Mar 24 20:40:05 myhost kernel: [5012215.155041] usb 8-4: Device not responding to setup address.
Mar 24 20:40:05 myhost kernel: [5012215.363022] usb 8-4: device not accepting address 71, error -71
Mar 24 20:40:06 myhost kernel: [5012215.703016] usb 8-4: new full-speed USB device number 72 using xhci_hcd
Mar 24 20:40:06 myhost kernel: [5012215.730479] usb 8-4: device descriptor read/8, error -71
Mar 24 20:40:06 myhost kernel: [5012215.862485] usb 8-4: device descriptor read/8, error -71
Mar 24 20:40:06 myhost kernel: [5012215.967082] usb usb8-port4: unable to enumerate USB device
Mar 24 20:40:07 myhost kernel: [5012217.051042] usb usb8-port4: Cannot enable. Maybe the USB cable is bad?
Mar 24 20:40:08 myhost kernel: [5012218.079014] usb 8-4: new full-speed USB device number 74 using xhci_hcd
Mar 24 20:40:09 myhost kernel: [5012219.047029] usb 8-4: device descriptor read/64, error -71
Mar 24 20:40:10 myhost kernel: [5012219.979025] usb 8-4: device descriptor read/64, error -71
Mar 24 20:40:10 myhost kernel: [5012220.087048] usb usb8-port4: attempt power cycle
Mar 24 20:40:11 myhost kernel: [5012221.063005] usb usb8-port4: Cannot enable. Maybe the USB cable is bad?
Mar 24 20:40:12 myhost kernel: [5012221.962998] usb usb8-port4: Cannot enable. Maybe the USB cable is bad?
Mar 24 20:40:12 myhost kernel: [5012221.963056] usb usb8-port4: unable to enumerate USB device
Mar 24 20:40:13 myhost kernel: [5012223.318987] usb usb8-port4: Cannot enable. Maybe the USB cable is bad?
Mar 24 20:40:14 myhost kernel: [5012224.218984] usb usb8-port4: Cannot enable. Maybe the USB cable is bad?

I redacted a bunch because it's just more of the same. The cable thing is an obvious possibility so I have a new one on the way, I'll see if that works.
 
I got a new cable and tried it, no such luck. The original location of the Teensy was next to some power cords so I tried plugging it into another USB port where it was far away from any other running devices, had the same problems. I got a new Teensy and set it up in the location where I was testing the old one, and it worked properly -- after uploading a sketch using serial comms, it presents /dev/ttyACMx and it stays up and works as long as I have it plugged in. I'm leaning toward there being something wrong with the board, but still I think if it had been electrically toasted it would refuse to work at all, not work for 2 minutes and drop.
 
The USB plug on the Teensy might be damaged/worn out, micro usbs have a reputation for wearing out.
 
That makes sense, it would explain the connection issues. Micro USB feels like one of the weaker links on many small devices like the Pi, I've wondered why Mini-USB isn't used instead. Because micro cords are more common for use as phone chargers?
 
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