Vintage Synth Repair

Hell List,

I have some question's about an Arp Sequencer :

It's Model 1621, is this the best model their was ?

It has also a problem ,their are 2 modes random mode en sequential mode,the random mode works, but with the sequential mode all the 16 LED's are lightning,this mean's the LED's are not moving.

Any Idea on what the fault could be,and the repairingcosts ?

thanx,
Arpguy