Recap JVC XL-Z1050 CD Player

[rhing]

I bought a JVC XL-Z1050TN CD player that was supposedly modified by Stan Warren for $100. It sounds really good, but on initial start-up, there is noise (like white noise, pink noise) coming through the left channel. This noise goes away after the unit has had time to warm up. I believe one of the electrolytic caps in the out stage PCB might be going bad. Considering that this 20+ year unit probably needs new electrolytic caps anyway, I took a look and identified the following caps in the power supply and output stage boards:


Power Supply:

1. 2x Nippon Chemi-Con AWF 2200uF/50V
2. 1x Nippon Chemi-Con AVF 100uF/50V
3. 1x Elna Silmic 100uF/50V
4. 2x Nichicon ES 220uF/50V

Output Stage:

1. 4x Rubycon MBZ 1500uF/16V
2. 3x Nippon Chemi-Con NX-V 2200uF/16V
3. 1x Nippon Chemi-Con NX-V 100uF/10V

Finding replacements for the Elna and Rubycon caps is no problem, but I can't find any datasheets on Nippon Chemi-Con AWF, AVF or NX-V. I believe the AWF and AVF caps are "audio" electrolytic caps. I can probably go with some Panasonic TS-HA and Panasonic FMs to replace those, unless someone tells me otherwise.

The green jacketed Nippon Chemi-Con NX-V (or NX-5) caps on the output stage board are a total mystery to me. I initially thought they were Nichicon ES nonpolar caps at first until I looked at them more closely. Here is a photo from this remarkable Lampizator Web site (Lampizator JVC K2 1050 CD Player with XRCD dac) that shows where these green jacketed caps are situated on the output stage board.

JVC XL-Z1050TN Inside 2.jpg

From the service manual schematics, they appear to be decoupling caps for the DAC.

Any assistance is greatly appreciated.

[stephensank]

That is not a typical symptom of cap failure, but it's possible. However, you can completely rule out any chance of the Nichicons being even slightly less than healthy, and it's very unlikely any of the Chemicons are dying either. It is VERY likely that the Elna & Rubycons are on their way out, though. But do yourself a favor & use Nichicons for replacements. Panasonics are as guaranteed to fail within a few years as any brand on earth(save perhaps Nover), being tied for worst cap maker in Japan(if not the world) with Elna(speaking from a reliability standpoint, which is as important to me as performance).
Your noise problem may be hard to track down, considering how short it's duration is. I would start by looking at the output of the dac with a scope at turn on, to see if the noise is before or after the output stage. If it's not coming out the dac, I'd start by going ahead & simply replacing the output stage chip/chips, and see if that cures it. If it persists, then you've got a job to nail down the cause.

[Lautar]

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[rhing]

Originally Posted by Lautar

servisemanual

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Thanks Lautar. I will check this out.