[GreenKeys] Teletype 28

[Greg Putrich]

Hi-

Have a problem with a model 28. The problem is that sometimes it prints
the wrong character. Sometimes it prints fine, but sometimes it gets messed
up (and is reproducible easily). It also has a tape attached and that works
fine (regardless of what the printer is printing).

For example, if I type HELLO WORLD, it prints out fine. However, if I 
type SCHOOL (usually on the right half of the carriage), then the O 
becomes M. It will continue to print M every time O is hit. If I 
type M, it still prints M. If the tape is punching at the time, it will be
correctly recorded on tape and will be read fine too. It's not just M & O
with the problem, but several other characters too, and not always the same
ones. 

There's a 2nd model 28 hooked up via current loop and it prints correctly
when data is sent to it from this one (the broken one prints SCHMML and the 
working one prints SCHOOL). If the typing is done on the fully working one, 
the problem still appears on the one that messes up chars. 

Does anyone have any ideas one where the problem could be? I've looked inside
quite a bit, but nothing obvious stands out. 

Also, does anyone have a service and/or instruction manual for it? We have
a couple of manuals that show the parts, but nothing that explains how
it operates or how to service it. 

    Thanks,
    Greg