Yamaha P-(X)50 Turntable DIY Maintenance Thread P-350, P-450, P-550, P-750, P-751, P-10, P-20

Discussion in 'Turntables' started by reydelaplaya, Aug 14, 2016.

  1. reydelaplaya

    reydelaplaya AK Subscriber Subscriber

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    As you all well know, I have a particular affinity for the Yamaha P-(X)50 series of turntables. This series, offered around the turn-of-the-decade 70s/80s, has often been my recommendation to fellow members when they ask about getting a nice vintage, consumer-grade turntable within a modest budget. They're well made, easy to operate, and have very good specs. IMHO, a great 'bang for the buck' turntable.

    Owning a couple, and having worked on a few, I have decided to provide some DIY maintenance walkthroughs to help resolve or prevent common issues that arise in this series.

    While there were some different options to choose from in this series, there are also parts that are common throughout the entire line.

    I would recommend downloading any manuals for your particular turntable from AudioKarma's AKDatabase or VinylEngine to assist in identifying parts, schematics, or any procedures. A link to the particular AKDatabase or VinylEngine page (if exists) is provided below by clicking on the model number heading.

    P-10
    [​IMG]
    The Yamaha P-10 is a 2-speed, belt drive, auto-return turntable. While it doesn't match the P-(X)50 nomenclature so I am not absolutely certain, this seems to be a rebadged P-350. While the P-350 was marketed as being semi-automatic, and the P-10 only being auto-return, the lifting mechanism is most likely the same as the lowering mechanism, which should make these tables physically and functionally identical. With that in mind, since a separate P-10 information page doesn't exist on VE, I have linked to the P-350 page instead.

    (This is just a guess, but from looking at it in a business perspective, it looks as if when the P-(X)50 series was discontinued and the later P-(X)20 line took its place, there were still some P-350s and P-550s left over. It appears they ended up getting rebadged and carried over to the bottom of the newer series.)

    P-20
    [​IMG]
    The Yamaha P-20 is a fully automatic, servo controlled, 2-speed, adjustable, direct drive turntable. Here again, like the P-10, this table is most certainly a rebadge. Having bought and serviced a P-20 as a gift for my parents last year, there is no doubt in my mind that the P-20 is actually a P-550. Excepting the labeling, everything inside and out is identical to the P-550 service manual. Since a P-20 information page does not exist at the moment, the link to the P-550 page has been provided. Also: See footnote in P-10 above.

    P-350
    [​IMG]
    The Yamaha P-350 is a semi-automatic, belt drive, 2-speed, servo controlled turntable.

    P-450
    [​IMG]

    The Yamaha P-450 is a fully automatic, belt drive, 2-speed, adjustable, servo controlled turntable.

    P-550
    [​IMG]
    The Yamaha P-550 is a fully automatic, servo controlled, 2-speed, adjustable, direct drive turntable.

    P-750 / P-751
    [​IMG]
    The Yamaha P-750/P-751 is a fully automatic, quartz lock, 2-speed, direct drive turntable with adjustable VTA. I own two of this model, and will be using the one that is currently on my bench for repairs as the model for photos in the subsequent write-ups.

    For the moment, I am leaving the P-850 off of this list. While I suspect it has a lot in common with the rest of the line, I am not familiar with, nor have I worked on its motorized tonearm and FWD/REV controls.

    This thread will be constructed in stages, depending on the topic addressed, and a linked table of contents will be edited in below as new topics are covered. I am also open to questions or suggestions, so please feel free to ask if there's something you'd like to see covered or discussed.

    - rey

    Disclaimer: I am not a Yamaha technician, I am only doing this for the enjoyment of helping others keep these great vintage turntables running even longer. The information provided is for reference only. Choosing to repair your turntable following the guides below is entirely a YMMV situation. There are no guarantees.

    References: Technical information provided above was sourced from AKDatabase and/or VinylEngine. All images sourced from the internet.


    EDITED to repair image source links
     
    Last edited: Jul 13, 2017
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  2. reydelaplaya

    reydelaplaya AK Subscriber Subscriber

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    Yamaha P-(X)50 Series DIY Maintenance

    Table Of Contents

    (Click on the topic below to be taken directly to the post.)


    Tonearm

    To Be Continued... Well, there's three and it's after one. Time for bed because tomorrow's another school day.

    ;)
     
    Last edited: Aug 16, 2016
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  3. kcblair

    kcblair Back to records

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    Nice, I thought I was the only Yamaha fanatic.......... :beerchug:
     
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  4. Crazy Gnome

    Crazy Gnome Staying Positive Dagnabbit

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    :thumbsup:I have a p20 and have been thinking about opening it up and doing some preventive maintenance.:trebon:
     
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  5. OMGCat!

    OMGCat! AK Subscriber Subscriber

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    Excellent write up so far!
    Thanks for putting the info out there. I am my P-751 will be waiting for further updates.
     
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  6. Rygen

    Rygen I can break any motor.

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    Yammy fan here, thanks for this.
     
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  7. reydelaplaya

    reydelaplaya AK Subscriber Subscriber

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    Yamaha P-(X)50 Series DIY Maintenance​

    Tonearm
    • Azimuth Adjust
    Tools needed
    • Slot-head mini-screwdriver.
    • Azimuth adjustment tool (if available)

    Sometimes the headshell and cartridge are not parallel with the surface of the record/platter. In an effort to get the stylus riding on the Y-axis optimally in the record groove, an adjustment may need to be performed.

    The P-(X)50 series tonearm has its azimuth adjust screws underneath the tonearm's headshell socket. I removed the tonearm for the sake of the photo, but it is not necessary, nor would I recommend doing so - having the tonearm attached and riding in its bearings is essential for this adjustment. Please pardon the oxidation around the screws. That part isn't removable, so it will need to just be oiled and stay that way.

    [​IMG]

    The two little screws closest to the center of the image are the azimuth adjust screws.

    DO NOT REMOVE THESE SCREWS

    For this job, all we need to do is just loosen them both a few degrees. Essentially as soon as they're no longer tight, they're loose enough.

    The best way I've found to do this is by using a little TechLine slot-head mini-screwdriver from a set I bought at Radio Shack in the 80s. I'm sure they're still sold somewhere.

    [​IMG]

    Key point being that it is short enough to fit into the slot-head screw fully from underneath without having to remove the tonearm. With this screwdriver set, there's still about 1/4in more that the tonearm could move up, so it's not putting any undue pressure on the bearings.

    [​IMG]

    [​IMG]

    Upon doing so, the headshell socket at the end of the tonearm will then become just loose enough (squeaky-loose is perfect) to twist to the correct camber. It only twists a few degrees in either direction from center, so be careful not to twist too much.

    Again, do not remove these screws. They screw through holes in the tube of the tonearm and into a locking plate on the inside. Removing these screws will set the locking plate loose inside the tonearm with nothing to help reposition it.

    At this point, remove the counterweight from the back of the tonearm.

    Since I do not have the tool I would need to have to set perfect camber on the headshell I had to improvise a solution. If you have an azimuth adjustment tool, use that. The process of twisting the headshell socket will still be the same.

    Pulling the stylus shell off my cartridge I realised that my cartridge has a perfectly flat bottom. I put the headshell into its socket with the stylus removed from the cartridge, and tightened the headshell lock screw.

    Then I removed the platter mat, leaving just the bare metal platter.

    Gently placing the cartridge onto the platter, I was able to see how well the azimuth was aligned.

    For the photo below, you can see that the cartridge is sitting on its inside corner, not perfectly level with the platter, allowing light to pass underneath its outer edge - or, negative camber.

    [​IMG]

    For the sake of this walkthrough, below is what it would look like with positive camber. Note the light coming through from the inside and the cartridge resting on its outside edge. These two pics show the extreme to which the camber can be set. Avoid over-twisting.

    [​IMG]

    To get the best possible azimuth setting either use the tool if you have it, or just get the bottom of the cartridge to lay perfectly flat on the platter. Lightly twist it one way or another until it does so.

    [​IMG]

    After the cartridge lays flat across the front edge and you're satisfied that it's in the right spot, lift the tonearm off of the platter by the cue up or by the metal tube as to not disturb the new azimuth setting and move it back to the tonearm rest.

    Little by little tighten both of those two screws from earlier, alternating between the two until they are tight again. They are not lug nuts, and do not need to be 'torqued down', just tight enough like before to hold the headshell socket in the appropriate place without risk of twisting again during regular use.

    Replace the counterweight, and rebalance the tonearm.

    It would also be advisable to recheck, and correct if needed, the cartridge alignment.

    All done!

    Click To Return To Table Of Contents
     
    Last edited: Jul 14, 2017
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  8. reydelaplaya

    reydelaplaya AK Subscriber Subscriber

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    Thanks for the support, guys!

    I really like this series of turntables. And in an effort to help those who have a TT in this range, I thought it might be fun to do a maintenance thread - so here goes! :)
     
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  9. reydelaplaya

    reydelaplaya AK Subscriber Subscriber

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    Yamaha P-(X)50 Series DIY Maintenance​

    Tonearm
    • Bearing Lubrication
    Tools required
    • Slot-head mini-screwdriver
    • Fine sewing needle
    • Q-tips
    • Paper towel
    • Mild cleaning solution (Windex)
    • Light machine or clipper oil
    Over the course of the last 35 years or so, the upper bearings of the tonearm on the P-(X)50 series turntables have had a tendency to have the original grease harden or get sticky. This causes the tonearm to not balance properly during setup, and ultimately renders any Vertical Tracking Force weight readings inaccurate. It can also play a significant role in mistracking when playing a record. If the tonearm doesn't 'float' in balance, and tends to stick up or down when nudged, it most likely needs to have the bearings cleaned and relubricated.

    Removing the tonearm, cleaning the bearing races, relubricating, and reinstalling is a fairly straightforward process, but it is a bit of a challenge. It requires concentration and a delicate touch. That said, a typical DIYer should have no problem completing the process successfully. I would recommend reading through the instructions below a time or two to familiarize yourself with the entire process before attempting it on your own table.

    Again, I'll reiterate, this is an 'at your own risk', YMMV type of maintenance. Please take that into consideration before attempting.

    Disassembly

    Start by unplugging the turntable and putting it on a clean, flat, well-lit work surface with the right side toward you. Remove the headshell and counterweight. Place your left hand on the platter with the spindle between your two middle fingers and place the tonearm between your thumb and forefinger as shown in the photo below.

    [​IMG]

    This grip on the tonearm allows for good leverage and stability without stressing it too far in any particular direction.

    Next, locate the silver plastic disk that covers the bearing screw on the pivot of the tonearm.

    [​IMG]

    With the fine point of the sewing needle, insert it at the gap between the metal base of the pivot and the plastic disk.

    [​IMG]

    Lightly pry the disk out by its edge, being cautious not to slip or mar the finish.

    [​IMG]

    Lock the tonearm in its rest, and repeat the disk removal procedure on the opposite side.

    The disks have a type of thin adhesive tape on their backs which hold them in place, and should be stored in a safe location, adhesive side up, until it is time to replace them.

    Underneath the disks, you'll see the upper bearing screws (silver metal, center) and the locknut (brass, outer).

    [​IMG]

    Insert the mini-screwdriver into the center bearing screw and attempt to back it out. It may be tight, and suddenly 'pop', so be careful. If the screw refuses to turn, the locknut may be preventing it. If you have a special tool that will grip the two slots on the outer locknut, I'd suggest using that to loosen it. If not, and you're lucky like I was with mine, insert the mini-screwdriver into one of the slots of the locknut, and turn it counterclockwise and it will loosen its grip enough to then allow removal of the center screw.

    [​IMG]

    Remove the center screw and locknut completely, and repeat this procedure for the other side. As you are removing the opposite side, be very careful with the tonearm. As it comes loose, it is very vulnerable to damage - especially the wires.

    [​IMG]

    Next, gently lift the tonearm out of its pivot and roll it over to one side or the other being extra cautious of the tonearm wires (moving it back, behind the pivot, may help). There should be just enough extra wire coming through the base of the pivot for this to be possible.

    If you feel any hesitation from the wires, stop, reposition the tonearm in the pivot, and replace the pivot screws enough to securely hold it in place - you may need to go inside through the bottom cover of the TT and see if the wires are catching on anything.

    [​IMG]


    If it is going as planned, lay the tonearm down on its rest with one side of the inner bearing accessible, and use the rest lock to lock it in place.

    [​IMG]

    [​IMG]

    Cleaning and Lubrication

    Add a drop of the light oil to the bearing race and let it soak for a minute or so. Take a piece of the paper towel and roll it into a small point. Insert the point of the paper towel into the center of the race and twirl it around to clean out any of the old gunk that's in there. Repeat this procedure, adding another drop of oil until you are satisfied that it is as clean as it's going to get. With another piece of paper towel, clean the outer area of the bearing, including that black circle that surrounds it. Get all of this area as clean as it can be.

    [​IMG]

    Unlock the tonearm, and roll it in the opposite direction to reveal the other bearing race. Repeat the above procedure, cleaning the inner bearing race, and outer area.

    At this point, it is the perfect time to take a couple of those q-tips and mild cleanser and clean the rest of the pivot, paying special attention to the areas that are permanently obscured by the tonearm when it's in place. Also clean the inner area of the pivot where the screws were.

    [​IMG]

    I found that pulling the cotton out a bit from the stick of the q-tip and twisting it tight gave a 'cleaning point' that was sturdy enough to 'screw' through the inner screw-holes to clean out any debris in there too.

    Now, place a fresh drop of oil on both bearing races, and re-lock the tonearm in the rest.

    Clean both bearing screws and locknuts with a drop of oil and a piece of paper towel so they're nice and shiny, and free of debris.

    Reassembly

    On both sides of the pivot, reinstall the bearing screws so that their points are flush with the inside surface of the pivot. Replace the tonearm into the pivot, making sure the wires feed effortlessly back through their hole. Holding the tonearm exactly in its proper place, slowly screw in the bearing screws until you feel them take hold in the bearing races.

    [​IMG]

    Center the tonearm in the pivot by adjusting the screws in and out, starting with backing one out a little, first, then screwing in the opposite side to match. It's easy enough to eyeball the centering, but if you have a feeler gauge, all the better. Do not over-tighten either screw.

    Once you've got it centered, replace the counterweight and headshell. With the thumb and forefinger of one hand, grasp the pivot directly at the bearing screws, and grasp the tonearm with the other hand. Gently wiggle to see if it is secure in its bearing. If it is wobbly, turn in each screw just a degree or so at a time, until it no longer wobbles, but is still floaty and free moving on its axis. This may take a few attempts.

    Afterward, balance the tonearm, and see if it free floats like it should. Bear in mind that this is a light tonearm, so some minor resistance may be induced by the rigidity of the wires.

    Once you're satisfied that it is operating as it should, replace the locknuts. Only screw them down to the point where they just become snug against the inner surface of the pivot. Avoid turning the inner screw during this process (possibly easier said than done).

    [​IMG]

    Re-test the tonearm for 'floatiness' - some delicate adjustment of the screws may be required to perfect it.

    If it is floating properly, replace the plastic disks, rebalance the tonearm, and check the alignment of the cartridge.

    Crack open a well deserved cold one...

    You're done! ;)

    Click To Return To Table Of Contents
     
    Last edited: Jul 31, 2017
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  10. reydelaplaya

    reydelaplaya AK Subscriber Subscriber

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    Yamaha P-(X)50 Series DIY Maintenance​

    Tonearm
    • Jumpy/Choppy Auto Return

    Tools Needed
    • Pencil with eraser

    For some reason, this particular series of turntable has had a presumably age-related issue with the smoothness of which the tonearm auto-returns to its rest.

    Before you pop off the bottom cover and lubricate every single moving part inside hoping to finally fix it and only end up disappointed, try this method.

    Unplug the turntable and clean the tonearm track (that black, semi-circular piece in the center of the image) with a mild, non abrasive cleaner.

    [​IMG]

    Next, after it dries, 'erase' the track with the pencil eraser, being careful not to get the eraser sheddings down inside the shaft or anywhere else they don't belong.

    [​IMG]

    Blow away any of the debris, then use the pencil lead to 'color-in' the entire top of the track. Make sure to coat it completely, but be careful not to get pencil dust all over the place.

    [​IMG]

    Once completed, blow away any debris/dust, and manually run the tonearm over the full length of the track to smooth out the pencil lead (graphite) coating. Apply just a light pressure while doing so. Then reapply another 'coat' of colored-in pencil lead. Blow away any excess.

    Plug the table back in, and test the auto-return. After a little dry graphite lubricant on the track, it should be smooth now, with no jumpiness.

    Click To Return To The Table Of Contents
     
    Last edited: Jul 31, 2017
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  11. Crazy Gnome

    Crazy Gnome Staying Positive Dagnabbit

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    Thanks. Major good karma going your way. Just finished the tonearm. It definitely needed it. Your post made it a breeze and without it I would have been lost.
    Went ahead and penciled up the rail for the auto return as well even though it didn't need it.
     
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  12. D4tubes

    D4tubes New Member

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    2
    Hello, Nice post here. Are you aware of any means of adjusting VTA on the P-350?

    Dave W.
     
  13. reydelaplaya

    reydelaplaya AK Subscriber Subscriber

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    Hi Dave. Thank you.

    I'm sorry, but aside from a different thickness platter mat, I don't believe there's any official way to adjust the VTF on any of the others outside of the 750/751.

    That doesn't mean it's absolutely not possible - there could very well be some type of vertical adjustment nuts at the pivot of the tonearm on the inside of the cabinet. But even if something like that exists, that's definitely an at your own risk, ymmv situation. If you're willing to take that risk, that's where I would start looking.

    Good luck with your table. Feel free to add any pics or info if you decide to open it up and find that it's internally adjustable.
     
  14. Broton

    Broton New Member

    Messages:
    6
    I love this thread.

    My P550's platter seems to be intermittently "rubbing/scraping"... I can't seem to see or find the source. Any ideas?
     
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  15. reydelaplaya

    reydelaplaya AK Subscriber Subscriber

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    Hi, Broton. Welcome to AK.

    I'd be happy to help figure out why your platter is rubbing.

    It's a bit late here tonight and I'm about to wrap up for the day. But in the mean time, please post a top down pic or two of the TT with the platter removed but with that whole area in view.

    I've already got an idea what it may be, so I'll take a look at your pics tomorrow and see what we can figure out.

    Again, welcome to AK.
     
  16. Broton

    Broton New Member

    Messages:
    6
    Here it is. There is a bit of discoloration (black areas)... the old owner said he used some spray graphite to lubricate. Which stains. It looks like some of the top paint is rubbed away. Added a close up of the groove. Looks worse than it used to be... last I looked. It is an intermittent rubbing.

    Snapseed.jpg IMG_3127.JPG IMG_3128.JPG
    IMG_3129.JPG

    Also... I think I need a new stylus or whole cartridge. One of the channels seems to not work or half work (low)... from time to time. I assume it's the head. But not sure how to diagnose. What kind should I replace it with and where?
     
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  17. Marine0811

    Marine0811 AK Subscriber Subscriber

    I have a Yamaha YP-D6, I run an Audio Technical cart. on mine. I'm not sure of the model, but I can let you know. I also have a Yamaha P550. Does yours have the typical problem where the dust cover hinges won't hold the cover up? Makes changing a record a pain in the ass. I haven't really wanted to try putting something in there to hold it in fear it could break the cover.
     
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  18. Broton

    Broton New Member

    Messages:
    6
    You run the AT cart on your P550? Or the other one? Would it work on the P?

    As for the dust cover, I have no such problems with the hinges... don't have hinges, don't have a dust cover! :) I drape a soft plastic cover over it when not in use. I have been looking for a cover but no such luck. No big deal... The rubbing and cutting out is.

    B

     
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  19. reydelaplaya

    reydelaplaya AK Subscriber Subscriber

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    Ok.

    Here's what I think. I can't guarantee 100% success, but this is where I'd start. Keep in mind, this is an at your own risk kind of job. There's really not much risk involved, I don't think, but if messing around with the inside of old electronics isn't your thing, you might consider asking for some help.

    It seems like your platter has had something very heavy placed on it at some point in time, or it was shipped/dropped with the platter in place. I've got a feeling that either the motor mount screws are loose, or mounting posts have stripped, allowing the platter/spindle to fall further than it should which causes the platter to rub against the chassis.

    First, unplug the TT completely, and move it to an area where you've got a little room to work. Then, remove the platter and headshell, and secure the tonearm to its rest. Next, since you don't have the dustcover, you'll need a couple thick books or something to support the TT while it's upside down so it doesn't rest on the spindle and tonearm.

    Once you've got it upside down and secure. Remove all outer perimeter screws and the gold colored center support screw from the bottom plastic plate. The feet screws do not need to be removed.

    Under the black plastic bottom, you'll see your DD motor mount. This photo below is of my P-751. It is not exactly the same motor you have since you have the Servo DD, but it should be something similar.

    [​IMG]

    I looked on vinylengine, but there is no service manual to your TT, so I can't upload a pic of the inside of yours, but iirc it should look more or less similar to this.

    Basically you're looking for the bottom half of the motor. (The big metal square with the white button looking thing in the pic above).

    Back out all four screws a little, and wiggle the motor mount while pushing down to ensure it is properly seated on its posts.

    [​IMG]
    [​IMG]
    [​IMG]

    You do not need to remove the drive unit to do this step. I only removed mine to show what posts I'm referring to.

    Once you're content that the drive motor housing is snug and seated properly on its posts, retighten all four screws feeling for any sense that the plastic of the posts might be stripped.

    If one or more of the posts' plastic is stripped, your best option besides replacing the posts (and I doubt you'll find replacements 40 years on - maybe @ organ donor, though) is to go up one size in screw. This needs to be tight and snug up against the posts so that it pushes the spindle as far out as it's supposed to be. If you need larger screws, take one of the existing to a hardware store and ask them for the next size up in shaft diameter.

    Try this, and see if that fixes it. And while you're in there, snap a pic or two of the insides, so we can see if there's anything else unusual.

    Once you've got it back in place, nice and tight, and the cover back on, turn the TT back over and replace the platter. Do not drop it on there, or push it down. Just place it onto its self-centering tapered spindle, and let it down gently.

    Then just give it a spin to see if it still rubs.

    If it doesn't rub, put the TT back in its spot, and for good measure, redo the cartridge alignment just in case the motor mount shifted a little.

    Good luck, dude. Let us know how it goes!
     
    Last edited: Jul 31, 2017
  20. reydelaplaya

    reydelaplaya AK Subscriber Subscriber

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    FYI, Organ Donor has 2 dustcovers - not pristine, but at least one that fits your TT (theyre under P-350, and P-450).

    They also have the complete motor assembly for your P-550 (no posts), and a spare headshell. If your fix works, and you plan to keep this TT for a while, I'd grab all of those items just to have - if nothing else, at least the headshell and maybe the dustcover.

    http://organdonorparts.com/Yamaha_c16.htm
     

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