"William Sommerwerck" wrote in message
. ..
When someone says their Selectric is suddenly typing the wrong characters,
I
wonder whether this is a troll.

The ball can be put on only one way, and locks in place. It isn't clear
how
it could suddenly slip.

The mechanism that moves the ball is, if I remember correctly, laterally
"balanced". If it broke, it seems the symptoms would be more serious than
just the wrong characters.


As well as the Rotate Tape and the Tilt Tape which shift the golf ball to
its various character positions, there are keyboard interposers and
selection latches, a couple of mechanisms which can result in suddenly the
wrong character being typed, without the character being in any way out of
place. It's been a couple decades since I used to fix hundreds of these,
though.

Henry Mydlarz