well hi the 1200 keyboard wont be of any use . l say just try give it clean check that all chips are seated . sounds like just the keyboard or the chip that controls it.
the flashing caps lock is to show something not working right.
somone sent me this link for my 2000 that keyboard doesint work at all
http://home.arcor.de/kickstart/TKA/Tutorials/troubleshooter/trouble2.htmlbut in all truth u most probably better taking to old tv repair guy that can look at for you
other wise you do more damage unless your good at fixing electronics that is
