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Repair hints: Technics SL-P101

Discussion in 'Electronic Repair' started by William R. Walsh, Jan 5, 2005.

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  1. Hi!

    I have the above mentioned CD player, pulled from a soggy cardboard box on
    trash day, along with some computer monitors and other stuff. The monitors
    have all been fine apart from some cleaning and the VCR has been working
    fine after I got it dried out. That leaves me with the CD player. It looks
    to be in awfully good condition for its age (not a scratch anywhere on it,
    not even on the display panel) and it powers right up with no problem. At
    present it has no problem reading the index of a disc, and it will play the
    middle and end of a disc with no problems. The only thing it won't do is
    play the beginning of a disc. I can see the spindle motor spin up and down
    and I can hear the laser sled moving around from time to time as the motor
    speeds up and down.

    I can only see one thing that's amiss when all of this is going on. The
    spindle motor seems to be having some moderate degree of difficulty coming
    up to speed. It seems to do so for the most part, but it takes what I feel
    is a rather long time. I am thinking that the spindle motor could be
    partially shorted and in need of a cleaning. I cannot check the temperatures
    of any driver components at present, because the components are on "the
    wrong side" of the boards.

    What I'm looking for is anyone who might have a CD player similar to this
    one in working order, for reference purposes. I'm curious how quickly the
    spindle motor in your player takes to come up to speed. If there is anyone
    out there who has seen a similar problem (like what are my chances...but
    there's no harm in asking...) with this player?

    Thanks in advance for any thoughts, tips, etc!

    William
     
  2. majortom

    majortom Guest

    Don't have any past experience with yours, but could be caused by the
    Servo Output IC. Chase the cables that lead from the drive to the main
    board, I'm sure the Servo IC will stick out like a sore thumb from
    there. Also check in that vicinity for signs of resistors that may have
    changed color, most likely not obvious with the naked eye, best to
    check them for tolerance. They should be resistors in the circuit
    between the IC and the motor itself.
     
  3. It's not the servo IC. Maybe a lubrication issue, many old Technics models,
    including I THINK yours, used direct-drive spindle motors.
    The sled drive wormscrews got bad lube and bad belts as well. Of course the
    optic should be cleaned.

    Mark Z.
     
  4. More likely cause is that the spindle motor is partially shorted. See:

    http://repairfaq.ece.drexel.edu/sam/cdfaq.htm#cdpwspmm

    --- sam | Sci.Electronics.Repair FAQ Mirror: http://repairfaq.ece.drexel.edu/
    Repair | Main Table of Contents: http://repairfaq.ece.drexel.edu/REPAIR/
    +Lasers | Sam's Laser FAQ: http://repairfaq.ece.drexel.edu/sam/lasersam.htm
    | Mirror Sites: http://repairfaq.ece.drexel.edu/REPAIR/F_mirror.html

    Note: These links are hopefully temporary until we can sort out the excessive
    traffic on Repairfaq.org.

    Important: Anything sent to the email address in the message header above is
    ignored unless my full name is included in the subject line. Or, you can
    contact me via the Feedback Form in the FAQs.
     
  5. It may be a partially shorted spindle motor - very common in many CD players.

    See: http://repairfaq.ece.drexel.edu/sam/cdfaq.htm#cdpwspmm

    The spindle motor has to spin faster on the inner tracks and can't make it.

    I doubt it's the servo IC as someone else mentioned. Could be mechanical
    though - deteriorated rubber parts, gummed up grease, etc.

    --- sam | Sci.Electronics.Repair FAQ Mirror: http://repairfaq.ece.drexel.edu/
    Repair | Main Table of Contents: http://repairfaq.ece.drexel.edu/REPAIR/
    +Lasers | Sam's Laser FAQ: http://repairfaq.ece.drexel.edu/sam/lasersam.htm
    | Mirror Sites: http://repairfaq.ece.drexel.edu/REPAIR/F_mirror.html

    Note: These links are hopefully temporary until we can sort out the excessive
    traffic on Repairfaq.org.

    Important: Anything sent to the email address in the message header above is
    ignored unless my full name is included in the subject line. Or, you can
    contact me via the Feedback Form in the FAQs.
     
  6. Stephen Sank

    Stephen Sank Guest

    The SLP101 has a linear motor tracking sled, so the lubrication of the guide rails is critical.
    Takes a very specific grease/oil(Panasonic molytone) to make it work properly. Probably the
    cause of the problem. With the unit unpowered, picking up the front of the unit 2-3" should
    make the laser slide smoothly from front to back, and vice versa picking up the back end.
    Otherwise, needs lube.

    --
    Stephen Sank, Owner & Ribbon Mic Restorer
    Talking Dog Transducer Company
    http://stephensank.com
    5517 Carmelita Drive N.E.
    Albuquerque, New Mexico [87111]
    505-332-0336
    Auth. Nakamichi & McIntosh servicer
    Payments preferred through Paypal.com
     
  7. Hi!

    Thanks to everyone for their excellent tips. I was leaning toward a shorted
    spindle motor, but the fact that the index was always read successfully made
    me wonder if that was really the problem.

    Cleaning the lens gave very little improvement and I did make sure it could
    slide back and forth freely. I started in to disconnecting all the cabling
    leading to the CD player mechanism and just as a guess, I reseated all of
    the connectors before taking the whole thing out to deal with the spindle
    motor. I couldn't see anything wrong with any of them, but the player is
    working perfectly now. There is no hesitation to spin up now, and the
    seeking seems to happen very quickly.

    I have never seen a player made quite like this one. It seems that the
    spindle motor servo controller is mounted to a circuit board that the
    spindle motor is also soldered directly to.

    William
     
  8. Great that it works. I would caution that when repairing CD players, often
    one does almost anything and they seem to be fixed, only to have the problem
    recur, sometimes weeks or months later.

    Mark Z.
     
  9. Absolutely! But at least what it confirms is that there is some bad
    connection or a crack in the ribbon cable, not likely a component that
    is bad.

    --- sam | Sci.Electronics.Repair FAQ Mirror: http://repairfaq.ece.drexel.edu/
    Repair | Main Table of Contents: http://repairfaq.ece.drexel.edu/REPAIR/
    +Lasers | Sam's Laser FAQ: http://repairfaq.ece.drexel.edu/sam/lasersam.htm
    | Mirror Sites: http://repairfaq.ece.drexel.edu/REPAIR/F_mirror.html

    Note: These links are hopefully temporary until we can sort out the excessive
    traffic on Repairfaq.org.

    Important: Anything sent to the email address in the message header above is
    ignored unless my full name is included in the subject line. Or, you can
    contact me via the Feedback Form in the FAQs.
     
  10. Hi!
    Makes me feel good to have saved it from the garbage, at least for the
    moment. :)

    I have played at least 20 CDs start to finish in the thing now and have left
    it running overnight on an 80 minute disc. The power went out last night,
    but this morning the player had the track list and total runtime on its
    display. I've "played the drums" on the top and sides, and twiddled all the
    around inside while it was playing. No change, although the pounding did
    make it skip, but that's to be expected.

    I'd like to think that it's fixed, but I will keep an eye on it. Why it ever
    broke I guess I will probably never know. Apart from the fact that it was
    soaking wet when I got it home, it doesn't look to have ever had anyone
    twiddling around inside or as though it has been abused.

    http://greyghost.dyndns.org/av/DSC02080.JPG (150+ KB, doesn't "do it
    justice"...but if you're curious...)

    William
     
  11. Or just moving and excercising various things including the mech can make
    them work for a while without ever revealing exactly what is was you did to
    "fix" the problem. This is one reason why so many techs (especially factory
    techs) replace pickups and whole assemblies. Fear of re-do's and time
    pressures not to really dig into it. I've seen little bits of hair or carpet
    fiber cause skipping problems, but replacing the whole mech fixes it as
    well.

    Mark Z.
     
  12. Guest

    Units exposed to water can have all sorts of weird problems occur,
    especially in electromechanical devices like cd players where there are
    very fine tolerances. Impurities deposited by the water , grit etc. can
    find their way into connectors, transformers , and almost all other
    places. If the unit is left as-is, corrosion and other problems can set
    in.

    Faults can take time to appear, even when the player has been dry for
    considerable time. I have found that dismantling the device totally (as
    soon as you get it away from the damp before rust sets in!), drying,
    re-lubing, checking all areas for deposits and cleaning can minimize
    the risk of problems. As you have found, reseating connectors is at
    least a good place to start!

    -
    Ben
     
  13. Hi!
    You don't say. :) I recently had a major sewer failure cause a backup of
    water into my basement. Nearly none of the CD-ROM or DVD-ROM drives that
    went under remain functional. It seems that the oldest drives took it a lot
    better (and held up to being cleaned in a much better way) than did any of
    the new ones. The drives run and "try to work" but I think that things
    inside the laser pickup got dirty when the water came along. I don't really
    know how to take laser pickups apart, if it can even be done. (And I have no
    desire to accidentally fry my eyes if the pickup were not to be quite
    correctly put back together.)
    This player was just set out in the trash, along with some computer monitors
    and a VCR. All of them were rained on, but the CD player and VCR were still
    mostly dry inside. The only places I found water in either one was around
    the openings on the case.

    Needless to say I mopped it all up and used gentle heat to encourage drying
    of components. It didn't look like any transformers had taken a "hit".
    Perhaps so. I haven't seen that effect myself--it has been my experience
    that if the device is cleaned up and dried out promptly that its chances of
    surviving are really pretty good. As it stands now I have played nearly my
    entire CD collection in this thing multiple times and it remains rock solid.
    I am going to hope for now that the connections had simply become marginal
    (this player is not exactly new) and that my reinserting them cleaned them
    enough to allow proper operations. If the player breaks again--I'll fix it
    if it is feasible to do so.

    I really think that the issue could have been one with a grounding contact.
    I have heard of electronics acting strangely when the grounds are not
    working for some reason.
    Indeed. I am very reluctant to grease or lubricate anything unless the
    material is clearly contaminated or I'm dealing with a fan. (Fans of all
    sorts, it would seem, act rather badly after they have been wet.) What
    lubricating material I can see in this player looks to be good, well
    distributed and not at all dirty.

    Given that it was picked up from a "high income" part of town and the fact
    that it is in nice condition, I'd say it lived a very nice and calm life
    until its owner found that it would no longer play CDs properly. Then out
    the door it went. Happens more often in that part of town than I'd care to
    talk about it. I've gotten a lot of really nice stuff just by waiting for
    trash day and then picking up whatever I find interesting. TV
    sets...Microwaves...whole computer systems (including some very modern
    ones)...misc stuff...

    I think that fully 90% of what I pick up could be resold for profit, but
    I've never done it that. What I can't use I give to others who need it more
    than I do. I find this kind of thing to be fun...and I think in my own
    little way that I'm saving the world from one more piece of equipment flying
    into an already overburdened landfill.
    It should have been the first thing that I did, but it was the last thing I
    expected given that it looked like the player had been well cared for and
    everything inside seemed to be in place. I think a lot of us could say that
    in regards to some things we have repaired! :)

    William
     
  14. The safety risk is minimal. It's more an inssue of if it's even possible to
    disassemble without totally messing up the alignment, breaking tiny wires,
    etc. Almost any contamination on the optical surfaces will cause the
    pickup to either not work at all or have degraded performance.

    --- sam | Sci.Electronics.Repair FAQ Mirror: http://repairfaq.ece.drexel.edu/
    Repair | Main Table of Contents: http://repairfaq.ece.drexel.edu/REPAIR/
    +Lasers | Sam's Laser FAQ: http://repairfaq.ece.drexel.edu/sam/lasersam.htm
    | Mirror Sites: http://repairfaq.ece.drexel.edu/REPAIR/F_mirror.html

    Note: These links are hopefully temporary until we can sort out the excessive
    traffic on Repairfaq.org.

    Important: Anything sent to the email address in the message header above is
    ignored unless my full name is included in the subject line. Or, you can
    contact me via the Feedback Form in the FAQs.
     
  15. Guest

    William R. Walsh wrote:
    (snip)
    I think there was a thread on a subject ike this in alt.dumpster-diving
    (or similar) a few years ago. amazing what you can find. More amazing
    (and worrying) is how people are prepared to just toss stuff, too.
    My parents-in-law have a house in the country fully kitted out with
    lamps, stereos, microwaves, clock radios, TVs/VCRs in all rooms, etc.
    purely thru' my scavenging/repairing, from years back!

    I find this kind of thing to be fun...and I think in my own
    Hear hear. I think it's also a great way of learning if you approach
    the repair task with an open mind and try to understand as well as just
    "fix". I have made many a good find in the street, although I don't
    often have the time to go hunting as much these days.

    regards, Ben
     
  16. NSM

    NSM Guest

    | My parents-in-law have a house in the country fully kitted out with
    | lamps, stereos, microwaves, clock radios, TVs/VCRs in all rooms, etc.
    | purely thru' my scavenging/repairing, from years back!

    Do pass the word around about http://freecycle.org/

    "The worldwide FreecycleT Network is made up of many individual groups
    across the globe. It's a grassroots movement of people who are giving (&
    getting) stuff for free in their own towns. Each local group is run by a
    local volunteer moderator (them's good people). ...

    One main rule: Everything posted must be free, legal, and appropriate for
    all ages. ... "

    N
     
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