Nakamichi 680ZX NO Sound

jonw

Active Member
I connected my new toy and no sound......
It powers up fine, the motor plays the tape, counter turns, but no sound.
Should the L and R levels move when playing a tape and not recording? If so there is no movement from the meters.

I checked the 3 fuses under the cover for continuity and they check out fine.

I know the RCA cables are good as I use them for my CD player.

Any ideas?
 
UPDATE,

I cranked my volume on the receiver and also on the "output level" on the deck and I get sound but at a VERY VERY low volume. Also the Right output produces NO sound.
Nothing is loose, burnt and all the caps have no bulges.

The machine will also play without a tape in it if that helps.
(I thought if no tape was present the machine would stop)

No idea what to check out next.:no:
 
99% sure it's a case of orange cap disease on the dolby/output board. I've worked on and own 3 680zx and all three had similar problems, all orange cap related. There's a bunch of them, but any of the ones from 1000pF to 3300pF should be replaced. I used Wima and Panasonic polypropylenes. There is also a real PITA one on the meter PCB that should be replaced. 1980 was not a good year for those orange polypropylene caps. Possible some of the electrolytics are bad as well.
 
99% sure it's a case of orange cap disease on the dolby/output board. I've worked on and own 3 680zx and all three had similar problems, all orange cap related. There's a bunch of them, but any of the ones from 1000pF to 3300pF should be replaced. I used Wima and Panasonic polypropylenes. There is also a real PITA one on the meter PCB that should be replaced. 1980 was not a good year for those orange polypropylene caps. Possible some of the electrolytics are bad as well.
Thank You for the reply!
Is there a way to check the caps or the board?
Or should I just replace them?
 
Is your STOP lamp burned out? If so, replacing it will restore your sound.

As a matter of fact yes it is........
Why would the lamp prevent sound?
I will replace it just curious how the two are connected.
 
Yes, Tom is right. They used the bulb as an actual part of the circuit. I always have just soldered in the resistor as soon as I get the decks, and forgot about it. I thought it would not go into play, though, not just no sound, but he's right, it's Mute activation. There is an official Nak fix, that is quite easy to do, NR-0039. Just solder a 1k ohm resistor between Pin 3 and Pin 8 on the dip (solder) side of Connector CN-8 on the Logic PCB. Good catch, Tom...I hang my head in shame...

However, still doesn't mean you still won't also have orange cap issues. Just replace them. You really have to pull them to test them, so you just may as well.
 
Update

I want to thank everybody! perryinva, Nakdoc, and Scorpion8 thank you, thank you, thank you! :music:
I soldered the 1k resistor to pin 3 & 8 on the logic pcb board and it works!:banana::banana:

Man does this deck sound great!!
I mean it REALLY sounds great!

I only have two cassettes.
U2 War and Jackson Browne The Pretender
 
I'm a huge fan of the 680ZX. A real classic, with rich analog sound, and the best meters ever built on any Nak, or any other deck for that matter. Glad it's working great for you!
 
Saw this post I did replace the bulb. So do I still have to solder a 1k ohm resistor to 3 & 8 of CN8?
 
No. If you have sound with the new bulb, then the resistor isn’t necessary. It just is part of the mute activation side. The resistor just allows mute to work with or without the play bulb operational.
 
I know this thread is kinda old, but THANK YOU to everyone who posted!

I have lusted after a 680ZX for my whole life and had a really, really nice unit fall into my lap at an excellent price. Original owner claimed it was perfect and it was...except: no meters on play. No output via headphones or RCA outs. Same exact thing the OP had.

Well. I just got done with the NR-0039 mod and it works great now. I'll replace the actual bulb(s) later, (the cassette well light is burned out in addition to the STOP button).

THANKS TO EVERYONE ABOVE!!!
 
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