Attempting to connect an AliExpress 1306 OLED to Teensy 4: insta-death :(

[10sy]

@PaulStoffregen: Thanks Master to enlighten me!!!

I opened that "jumper" to separate VUSB and Vin. (to separate VUSB to 3.3V converter part - I thought opening jumper is good idea)

I hooked up a button battery and Teensy blinking again with external 3.3V !

However there is no USB then (I guess because I opened that jumper).

What I need to do for working USB?

I'm really happy to see Teensy is not died, thank You sooooooo much!!!

[PaulStoffregen]

Try connecting 3.3V power to both VIN and the 3.3V pins.

Also for testing, after you press the button, the orange LED should turn off and the red LED should light. If there is no USB communication, the red LED will blink.

[10sy]

Try connecting 3.3V power to both VIN and the 3.3V pins.

Also for testing, after you press the button, the orange LED should turn off and the red LED should light. If there is no USB communication, the red LED will blink.

I connected 3.3V to VIN and 3V3 on Teensy - orange blinks, I'm happy.

At the moment I connect USB cable cuses OverVoltageProtection in the PSU and PSU switch off it's power output. I'm unhappy

Teensy still alive

[defragster]

I connected 3.3V to VIN and 3V3 on Teensy - orange blinks, I'm happy.

At the moment I connect USB cable cuses OverVoltageProtection in the PSU and PSU switch off it's power output. I'm unhappy

Teensy still alive

Perhaps cutting the VIN<>VUSB trace on the underside will allow programming/SerMon for that Teensy when powered directly as above with 3.3V.

[10sy]

Perhaps cutting the VIN<>VUSB trace on the underside will allow programming/SerMon for that Teensy when powered directly as above with 3.3V.

You are right: I was unsuccessfully cut VIN<>VUSB second time... For the bare eyes was clearly separated but it was'nt in reality as the mulimeter shows...

I fixed my bad, now PSU not starts crying on Over Voltage.

I connect USB and blinking continues. However now Windows says:

"Power surge on the USB port: Unknown USB device needs more power than the port can supply. PSU displays 3.3V/86 mA usage."

When I push the button orange blinking stops but red led doesn't light up.

Is that unsuccessful VIN<>VUSB separation may did it's nice effect (?)...

If I hold the button for 15 sec then red LED lights up in full static brightness. After a few seconds it's light off and orange starts to blink. Windows displays it's problem with USB surge....

[defragster]

That trace on the PCB is persistent!

"Power surge on the USB port: Unknown USB device needs more power than the port can supply. PSU displays 3.3V/86 mA usage."

Odd, with that trace cut the only expected path to PC is GND - is the external power on common GND and alright?

I had an RGB LED display matrix running once with enough power from 5V USB external supply - but weak GND between matrix and external power supply - so it was passing over 1AMP over GND with PC through Teensy. The PC handled it - but it kept me from being able to program normally at times. I added second GND wire to that external PCB to GND common to external display and it found a better path than the PC.

[10sy]

That trace on the PCB is persistent!



Odd, with that trace cut the only expected path to PC is GND - is the external power on common GND and alright?

I had an RGB LED display matrix running once with enough power from 5V USB external supply - but weak GND between matrix and external power supply - so it was passing over 1AMP over GND with PC through Teensy. The PC handled it - but it kept me from being able to program normally at times. I added second GND wire to that external PCB to GND common to external display and it found a better path than the PC.

PC & External PSU on the same power outlet, there is 7mV between PSU GND and USB GND. Do You mention to cut off USB GND (or I misunderstand You)?

My connection to external power and Teensy is good enough (0V)