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Need help with a Discman

Discussion in 'Discmans, Minidisc, DCC and other players' started by enryfox, Nov 26, 2017.

  1. enryfox

    enryfox Active Member

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    I have bought for cheap a SONY D-247 which was sold as "working". On arrival it would actually not play any CD and it would struggle to find focus. Sending back the unit was a non-sense as shipping cost equalled the CD player cost so I decided to try to fix it.
    It was still factory sealed, nobody had ever took it apart; everything looked fine, no leaks, no bulging caps, all tidy and clean; the calibration procedure, as outlined by the service manual, requires tools I do not have so I went the old way, trial and error with several CD's.
    Three regulations are available, tracking balance, tracking gain and focus gain: the first one made tracking worse in both directions so I assumed it was correct as it was. The two gain settings instead magically fixed most of the problems: by turning both 90~100 degrees clockwise (according to the service manual, decreasing the gain) the cd player now reads almost all my CD's, even CD-R mastered 15 years ago.
    There are still a couple of CD's which are hard to read, but I found out they can be easily read if the CDP is powered by the power supply instead of two rechargeable's.

    I anyway guess something is not right with this CDP, could be the laser diode nearing its end-of-life or it might just be a faulty capacitor ? Has anyone experience with this line of Discman (D240, D245, D247, ...)

    Sound-wise it is pretty decent and I like how it sounds, it has very deep bass, plus it has ESP so no skipping at all.

    thanks
     
  2. Jorge

    Jorge Active Member

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    My first guess would be that someone pressed CD onto TT a little too hard and the platter got pushed a bit towards the motor (and laser). Since SM does not specify the distance between the platter and motor, there is nothing you can do here except doing what you just did. Another time, when I had similar problem with D-90, recapping all electrolytics around the servo fixed the problem. These tiny electrolytics, when going bad, they (almost) never bulge and not always leak. Even when they leak, in most cases you know it only during desoldering by the nasty smell, and then by oxidized board traces right under the cap: see photo No. 7 in my post here.
    If you have a voltmeter, go thru the steps of Electrical Adjustments from SM, but it it sounds like it needs a recap around DC-DC converter anyway. Those caps (almost) always go bad. Do not be afraid to clean the lens with a q-tip and some lens cleaner. I prefer the ones branded by Zeiss. Try not to use Windex, it does etch the glass!

    You may also ask Kaosun at kaosuncd.com. I am just doodling with Discmans to keep my "idle hands" busy, but Kaosun fixed thousands (!) of Discmans. He does not bother himself with Sony Discmans produced after 1989 (well, except D-J50;)), so don't be too surprised/upset if he ignores your question.
     
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  3. enryfox

    enryfox Active Member

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    I know it is not a valuable CDP, but it sports very nice features like ESP and a real resume function(like a tape walkman) while still retaining analogue volume control.
    The unit I have is not exactly in good optical condition, the CD door has worn signs but it appears that that type of finishing is prone to scratches and marks; not sure if it is worth trying to fully recap or just find another one in better conditions reported as fully working (most CDP of late 90's are still perfectly functional); to my knowledge the capacitors issue is limited to units until early 90's: I have some walkman's from 1997~99 and they all work flawlessly with all original capacitors. I would be surprised if this CDP had actually capacitors issue, it is rather recent and not a low-end model.

    Anyway I have a couple of questions:

    1) the DC-DC converter is used only with the power supply or also with batteries ? not sure if the same circuit can operate as a step-down (4.5V -> 3.0V) and a step-up (2.4V -> 3.0V) converter. I use the CDP almost always with batteries
    2) only aluminium electrolytic capacitors are to be replaced ? do I also have to replace tantalum capacitors ?

    thanks
     
  4. Jorge

    Jorge Active Member

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    I wonder if anyone here would care to answer,... myself, I always just follow Kaosun's advice and recap before looking any deeper... But I also do not bother with post-1990 Discmans, PM me its SM to check DC-DC links there.
    Tantalum caps should be OK, that much I do know...
    Actually, electrolytics should be fine in your baby as well, so I will stick with my first idea of a platter being pushed in a bit
    Or some other crazy glitch, in a day or two I will give a link to my (successful) efforts of fixing my Wadia 781i: some real surreal stuff can happen during CD spinning...
    While waiting, post your Q at kaosuncd.com: this forum here is all about tapes/analog, so folks just dont care...
     
  5. enryfox

    enryfox Active Member

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    The SM does not even have the schematics, I think Sony just assumed that in case of problems the whole logic board was to be replaced.
    Anyway I got confirmation the DC-DC converter is used both for external power supply and batteries (which makes sense actually): I checked the voltage as indicated in the SM and levels are the same regardless the power source. What is strange is that the SM says voltage should be 3.0 V and in my CDP the level is 3.0 when doing focus search, but as soon as focus is found and normal play starts, level drops to 2.8 V. Might be a fault or might be a power save strategy.

    I have selected all replacement caps from Farnell on-line, but i'm afraid they might be too big: caps are all concentrated in one area which is pretty crowded and in some cases Sony opted for lower voltage cap (e.g. 6.3V vs 10 V or 16V) to decrease the size of the cap itself; but some capacitors are no longer available with such low voltages and thus they might be too big to fit.
     
  6. enryfox

    enryfox Active Member

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    I posted a couple of query's on kaosuncd forum but, as you warned me, I got no reply so far. The forum is also configured not to exactly encourage new members and new posts: ton of verification codes, need to set an avatar, ... Also there are very few members and threads: if walkman enthusiasts are a small group, discman/ portable CD players enthusiasts must be an even smaller group.
     
  7. Jorge

    Jorge Active Member

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    Since I was the one who asked Kaosun (thru head-fi forum) to setup his own Discman repair site, I did my best to keep conversations alive, then got tired... And yes, unless I intervene it takes him weeks to answer, if at all.
    His usual answer re dim display: check power supply. If there is some power problems, display goes out first
     
  8. Jorge

    Jorge Active Member

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    You've got your Q answered from Kaosun himself!!!
    Am I good or what? ;)
     
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  9. Jorge

    Jorge Active Member

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    Analog RULES! but I got a few thou of CDs which I tend to listen to every day, boxes of "Classical Music" CDs keep piling up (I strongly recommend "The Rest is Noise" by Alex Ross, I absolutely agree that "classical music" is a misnomer!) so here is my list of CD spinners for your bedroom or office. Definitely NOT for your big-rig stereo...

    the cheapest yet decent spinner: Sony D-90:
    L1120960.JPG

    The BEST Sony Discman out there, D-50MkII (sometimes D-7):
    L1120959.JPG

    the Best non-Sony Discman from Denon, from kaosuncd.com (DPC-50 upgraded to the "unobtanium" DPC-150 status by kaosuncd.com:
    L1120962.JPG

    If looks are of any importance, then this Denon spinner branded as Radio Shack/Realistic is my fav:
    L1120963.JPG

    For the brand-conscious, another UFO spinner from Philips:
    L1120966.JPG

    And the sexiest "Do We Find Somethin Small.." Sony:
    L1120964.JPG

    And lets not forget that outside of Sony, Philips and Denon we had some other winners:
    L1120965.JPG
     
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  10. enryfox

    enryfox Active Member

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    Thanks ! Hope Kaosun was not too disappointed for the low value CDP's... looking at the forum he's used to another level of players.

    As much as I hated Sony back in the 80's and 90's I now love their stuff from back then. From the list above I really like the D90 and the D50 (I am a fan of essential designs) while I do not like the third one, an excellent example of the Sony "I can make it smaller" approach to design.
    My main CDP is still a Philips, but on portable players I am now a bit scared by that brand as there is always a piece which will break: in my CDP i had to replace the tray gear but luckily a replica was available; walkman's and tape deck are (in)famous for melted plastic gear.
     
  11. Jorge

    Jorge Active Member

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    Absolutely! Philips AZ6892 has no problems with any gears but its laser looks like this:
    L1070343b.JPG
    I bought four(!) more Philips Discmans with the same RDC2 laser and all of them looked like this. Kaosun managed to fix one, so that I could have one UFO-Discman from Philips.
     
  12. enryfox

    enryfox Active Member

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    wow, I guess it was made with the wrong metal, that looks like heavy corrosion and a chemical reaction with humidity in the air !

    I have one "discman" from Philips.

    IMG_0626.JPG

    I bought it new in late 90's for its CD-RW capability, but it has a very plasticky feeling and it is the worse looking CDP I have (the box is ugly too). The laser is still in good condition, but the spindle motor rattles. Apparently it still works, but its service mode says the spindle motor is faulty (good to get a confirmation but I knew it from the start) as it does not reach 80% of target rotation within a fixed time. It was perfectly working when I shelved it in the early 2000's, but after 15 years of idleness it failed. That's so Philips ...
     
  13. enryfox

    enryfox Active Member

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    Going back to the original topic.
    I think you were right all along with your very first suggestion. By chance today I checked the lase pick-up and noticed this (not sure why I did not see it before)

    IMG_4723.JPG

    The plastic casing of the laser assembly has a crack which is a close match to the shape of the disc spindle. The plastic casing is also misaligned but that might not be the actual issue. Not sure of what happened as the motor spindle appears to be fine and rotates freely, but that means the player has been mistreated. No point in investing any money to fix this player, it works as it works (reads ~ 95% of CD's) and I will look for another one in better shape.

    thanks !
     
  14. Jorge

    Jorge Active Member

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    Two small flat screwdrivers on the opposite sides of CD "platter" and you can pop it up a bit. Sometimes I manage it using just fingernails (this reminds me of my all-time fav audio-conversation: Q: How is it possible to flip LP on a platter without stopping turntable first? A: Why do you think God gave you fingernails? Use them!)
     
  15. enryfox

    enryfox Active Member

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    That is what is strange to me: the clearance between the spindle and the laser pickup is more than 1 mm: to have the CD spindle touch the black casing I would have to bend it excessively while it is perfectly flat. Either the motor was replaced or something quite odd happened.

    ps. with a LP12 turntable, you have to learn to flip LP's with your fingernails... and luckily they are all 33 RPM not small and sharp 45 RPM...
     

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