My pico ist unable to activate the bootloader to upgrade the firmware 1.93 to 1.99

Tue 2018.10.09

I'm with @Gordon on this, as requested in #32 above, would you respond with what this does please:

digitalWrite(LED2, 1);
and after a brief period
digitalWrite(LED2, 0);
digitalWrite(LED1, 1);

ref: http://www.espruino.com/Pico+Buttons

I'm bewildered with how the LEDs sequence in one manner, the very instance that indicates the flash process is underway, which implies the button press had to have been recognized. The board can not be stuck in bootloader mode, as it has been indicated that coding is possible. #34

It is also not clear as to whether the Green LED has ever been seen illuminated. Both of us would like confirmation that the LEDs do in fact illuminate on command.

Then attempt
setInterval(function() {
digitalWrite(LED2, digitalRead(BTN));
}, 20);
and press the button with fingernail several times. What is witnessed?

Ref #25 are you willing/able to provide a short video on the cable connecting process during flash?