Fairlight-CMI

Hello,

after connecting the communication cable from the keyboard to the 
mainframe, with the power on, my system doesn't start up anymore 
(static electricity). It only shows a green square on the monitor and 
the keypad of the music keyboard doesn't show any text at all. I've 
checked all the fuses on the back of the mainframe, they all are OK. 
Also disconneced the music keyboard and plugged the qwerty keyboard 
directly into the mainframe. Also no effect. I can here the diskdrives 
running when I put in the boot disk, but nothing changes on the screen 
or keypad.
Did anybody else have experience with this problem? Are there also 
fuses on the cards inside the mainframe? If not which card could have 
something to do with this problem?

Thanks in advance

Hans