How to reset Teensy++ 1.0

For anyone who finds this later:
I can confirm Teensyduino 1.18 works with original Teensy++ and requires Arduino v. 1.0.5 available here:

Are you using TeensyDuino 1.18 and Arduino 1.0.5 per the thread you referenced?
Turn off Auto mode in the small Teensy Loader window, and keep it visible while you try this test.

Physically unplug the USB cable, and then hold the pushbutton while you plug it back in. While watching the Teensy Loader window, release the button. If the hardware is still working, you should see Teensy Loader detect it.

If you get no response in Teensy Loader, you could start trying to diagnose what's wrong with the hardware, like measuring the USB voltage. But to be realistic, if that 14 year old hardware is damaged, probably not worth a lot of effort.
There is no reaction in Teensy Loader. It does get recognized by Windows though. I also have some old Atmel Driver I used back then but they don't work with 64bit.^^
Maybe the code I flashed back then broke something or its just too old and some circuit broke after all those years.
But thanks for the effort :)