Sony CDP 350 help needed!

Discussion in 'Digital Sources' started by savv, Jan 3, 2006.

  1. savv

    savv Super Member

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    Got this at a local SA for $5. Tested it and was working fine until I got home and plugged it in. Disc information is not read, no disc error message. Disc just spins even when I press stop. Cleaned the laser lens with 91% alcohol and Q tips but problem persists. Is this a bad laser assembly? :sigh: any ideas appreciated.
     
  2. dr*audio

    dr*audio Fish fingers and custard! Subscriber

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    Rule #1, NEVER use Isopropyl alcohol on the lens! It is polycarbonate and the alcohol can cloud it. Use Ethanol or water.
    Since the disc motor is turning, that means the player has acheived focus lock, and the laser may be ok. There is a home switch that senses when the pickup is in the home position, all the way to the front. When the player starts, the first thing it does is move the pickup to the front until the home switch activates. The switch is located on the bottom of the mechanism, on the pc board with the disc motor and sled motor. You have to remove the mechanism to get to it.
    1. Turn the power on and push the drawer open button.
    2. Turn the power off with the drawer out.
    3. Remove the front cover on the drawer, by sliding it upwards.
    4. Turn the power on and allow the drawer to go in and the mechanism to load. Turn the power off.
    5. Now you can remove the mechanism, I think there are 3 screws. Make note of which cable connects where.
    6. On the bottom of the mechanism, right below the disc motor you will see a pc board. In between where the 2 motors are soldered you will see 2 pins for the switch. Read across the switch with an ohm meter. If you read more resistance than 0 ohms, the switch should be cleaned.
    7. De-solder the pins on the motors, and remove the board. Now you can see the leaf switch.
    8. The leaf switch has a plastic cover over the end. The cover has a step in it. Make note which way the step is facing, then gently pull the cover off.
    9. Lightly burnish the contacts of the switch with 600 grit sandpaper, then clean all residue from the contacts with alcohol.
    10. Gently replace the cover on the switch, and re-assemble everything.
    11. When you get it reassembled, power the unit up and open the drawer. Apply a drop of 3 in 1 oil to the bearing at the base of the disc motor.
    now it should work, unless the laser power is too low to actually play the disc.
     
  3. savv

    savv Super Member

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    Dr Audio,

    Super instructive! I will give it a try! I'm sure others will benefit from your post.

    Does this apply to all / most vintage Sony cd players?

    Thanks again. :thmbsp:

    Savv
     
  4. dr*audio

    dr*audio Fish fingers and custard! Subscriber

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    Yes, all Sony's are pretty much the same, except for the ES models. Additionally, when you power up the player, the pickup moves forward until it closes the home switch, then moves back a bit. If it just moves forward without moving back, the switch isn't working. Most other players do have a home switch, and operate the same way. All Sonys will not spin the disc if they don't have focus lock. If it spins the disc and reads the table of contents, but won't play, usually the laser is bad.
     
  5. savv

    savv Super Member

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    Warren,

    I opened it up but was only able to go to step 6 since I don't have the skills to unsolder / solder.

    Just put a dab of 3 in 1 oil on the bearing.

    Anyway, I discovered that the only way this player will recognize a CD is when I tilt it upwards (table of contents or track numbers will be shown). Then there is the other matter of getting it to play. I have to repeat the same procedure and will play tracks but will skip intermittently.

    What do you think? An alignment issue. poor laser?

    Also there is noise from time to time (like static).
     
    Last edited: Jan 5, 2006
  6. dr*audio

    dr*audio Fish fingers and custard! Subscriber

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    The player is designed to be level when it is playing a disc, so it could be skipping because of that. Tilting the player should not affect the home switch, so maybe soemthing else is going on. If you leave the player level, do you hear a tick, tick tick as the disc rotates, like something is rubbing? If so, see if the ticking slows down if you gently put your finger on the cd to slow it down. If so, something is rubbing, possibly the chuck that holds the cd is rubbing against the arm. Sometimes the shock absorbing springs on the mechanism get compressed and the mechanism sags, causing the chuck to rub on the arm. You can stretch the springs out by the distance of about 2 turns.
     
  7. savv

    savv Super Member

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    Ticking remains constant even after I put my finger on the cd to slow it down.

    For what its worth, when I press eject and the tray opens with the cd, it does not open all the way perhaps leaving 1/2" of the tray inside. I can coax it gently to open all the way. If I don't coax it so that it fully opens, I hear a whirling sound. This only happens when a cd is on the tray. Without a cd it opens and closes with no problems.
     
    Last edited: Jan 5, 2006
  8. dr*audio

    dr*audio Fish fingers and custard! Subscriber

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    The ticking that you hear, in this case, is probably the laser trying to focus. The drawer problem is probably the belt that moves the drawer. Still don't know why it would work when it's tilted back, unless the home switch is dirty and the mechanism is getting jammed in the home position. Try it in the tilted position, get it to start playing then put it down flat and see if it still plays.
     
  9. savv

    savv Super Member

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    I discovered that the player would respond when I push down on front cover of the tray on a tilted position. Then I put it down flat and it plays ok except for some intermittent noise and a few skips here and there.
     
  10. dr*audio

    dr*audio Fish fingers and custard! Subscriber

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    Sounds like it needs a new loading belt.
     
  11. savv

    savv Super Member

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    Warren,

    I found only 1 belt in this unit. Is this the one underneath the mechanism near the front? Visually the belt looks ok but do you mean that it may have been stretched? Where can I get belts for these? I also need a new belt for a Yamaha CD 400.

    Thanks.
     
  12. dr*audio

    dr*audio Fish fingers and custard! Subscriber

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    Location:
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    Yep, that's the one. They get stretched out after awhile and slip. You can try cleaning it with ethanol (vodka will work). If it works better, you know to replace the belt. www.mcmelectronics.com has belts in various sizes. You can measure the one that is in there:
    Stretch it between two pencil tips next to a ruler. Stretch it just enough to get the slack out, and measure the length. Multiply the number by 2 to get the circumference, then measure the thickness. Buy a belt one size smaller to account for stretching. Or you can try this place:
    http://www.partstore.com/
    You can search by model number and the part you need.
    or try Sony:
    http://servicesales.sel.sony.com/web/index.jsp
    If they don't list the part for your model, try their live chat, they may have a cross reference.
     
  13. Novice2017

    Novice2017 New Member

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    From the fact that the Sony CDP-350 and CDP-550 have the same User Manual (Operating Instructions), I assume they are very similar players. My question is: Is there a way to remove the CD tray of the CDP-550 (without damaging any gears by pulling it forcibly out) and then reinstall it and ensure that, when the tray is completely closed the laser will be raised in its normal play position? Unlike postings about other CD players that I have seen, which allow the tray to be lifted straight up out of the unit in the "play" position (which makes it much easier to reinstall it and keep it in sync with the laser pickup assembly), I cannot see how that could be done for the CDP-550. Any help will be very much appreciated.
     

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