I got Nakamichi 1000MB that won't eject. New belts. Here are symptoms. When pressing eject the laser/motor will come down like it supposed to but nothing after that. It does sense that nothing happened after several seconds and ties to play disc again. The mechanism and electronics for this are almost identical to a cd player 3(main difference MB1000 has servo motor for disc). If I take mechanism out of this and put in cd player 3 it will eject. The only differences I detect is CD player 3 has 15 volts going to eject IC LA6520 with 5.9 volts going to motor and 13 volts for 1000MB with 4.6 going to motor. The 1000MB will eject if you pull cd drawer about an inch when time is correct for it to eject and it will load fine if it is already ejected. What I tried already- Changed LA6520 IC and the 64 pin mechanism IC(they are identical in the 2 models). No difference. This has got me stumped. Any suggestions?
Well yes it's using an unregulated supply with a couple 2200uf caps if I remember correct but I just discovered something else. I was finally able to get right at motor with test(not easy due to how this is made since this one won't work out of the machine like other musicbank ones will) and I am getting about 0 volts when eject is pressed even though I'm getting 4.6 V at motor output IC. I also discovered when loading disc I'm getting 5.9 V like eject should be. The output of motor IC goes directly to motor so something really screwy is going on here.
I've heard of a Shigaclone but never heard one. This Nak was considered to be the best transport out there when it was released according to magazines but didn't hold that title long as a Mark Levinson(can't remember the model) became the best within a year after release so many forget how good this one was. It sounds exceptional to me but I haven't directly compared it to anything else high end. This is super well built is air tight(nak called it vaccum sealed) and had the same type of DC servo moter the dragon casette had. Just looking at the service manual of the Dragon CD the 1000 looks to be much better made. The dragon CD does not even have a dc servo motor according to manual and the whole thing appears to be a modified car changer combo. Just the 1000 transport weighs about twice as much as the dragon CD transport part. If anyone else knows about this unit and the Shigaclone mabye could chime in on the subject .
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