@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!!!
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!!!