owerbook Duos

The Duos are an even more portable Powerbook. The difference is that you must dock them with an adapter to get connections to the outside world.  The upside of a Duo is that docked in the Duodock you have a full blown desktop Macintosh at your disposal. Enough teaching. If you have a Duo you know what it is.

The Duos have been remarkably reliable. The only problems were with a non standard modem protocol that is beyond help here, and another problem with the keyboard.

Keyboard Problems
Some of the earliest Duos had a poorly designed keyboard.  Oh, it would type good and last as long as the others but it would short and cause some keys to repeat or be skipped as you typed.  If you have one of these you must get a replacement. If you want to be sure it is a problem one and can take your Powerbook apart, then look for the serial number on the bottom of the keyboard. The newer ones have a B at the end of the serial number. 
By the way, if you still have problems it is probably because of tight screws when the powerbook was taken apart. Loosen them up a bit and the problem will go away.