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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    Aguadilla, PR
    The plastic on the hinges is a common fail point where the tension spring finally breaks through. There's a fix around here somewhere where holes are drilled in the plastic and a brad/fine finish nail is passed through creating a new support for the tail of the spring.

    There are also several different, all-metal hinges that from different manufacturers that will fit. I know some model of JVC TTs fit because that's what I'm using on my own. Linn also fit, but they're kinda expensive.

    Check the auction sites for TT hinges, and look for the correct shape. The only thing needed to be a perfect fit is a couple of felt shims.

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  2. Broton

    Broton New Member

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    6
    WOW. Simply amazing. Thank you so much for that effort. I look forward to try this... need some time and space. But looking forward to seeing if this does the trick.

    Thanks again! And I never heard of organdonorparts great site.
     
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  3. reydelaplaya

    reydelaplaya AK Subscriber Subscriber

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    You're welcome, @Broton. I hope that it's an easy fix like I've described. That's a great TT from Yamaha in that model line - in fact, I think it was probably their top of the line from that series - with the 750/751 being a close second. I think it's definitely worth trying to repair and hang on to for a while. Let us know how it goes. And if you run into any problems, just post in here.

    As for your intermittent sound from the cartridge, try gently unplugging and re-seating the cartridge wires. Sometimes it's as simple as a poor connection back there.
     
  4. Broton

    Broton New Member

    Messages:
    6
    Well... I did my best. As instructed... and sadly to no effect. It looks like the plastic feet and the motor housing is in there solid. No play whatsoever. Backed out the screws and tightened again. Still rubbing. Also... there now seems to be a bit of "steppyness" to the motor when running. I have never run the motor without the platter before... but there seems to be a bit of give and go to it's movement. Was it there before? I cannot say... but don't recall. Maybe that's how it should turn. My feeling is not... I assume the motor should rotate constantly and silently. Probably made more of a mess of my situation. Le Sigh.
     

    Attached Files:

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  5. reydelaplaya

    reydelaplaya AK Subscriber Subscriber

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    Don't give up, we're not done yet.

    As for the jitters, yeah, the motor needs the platter mounted in order for it to stabilize its speed. It uses the momentum of the spinning disk to help maintain proper speed. When the platter isn't there, it gets jerky. My 751 does the same thing without the platter, too. If I've learned correctly here in AK, it's the space between the poles of the motor that causes it.

    So it still scrapes?

    Hmmm... And you didn't notice any other screws or anything that looked loose while you were in there? From what I see in the pics, probably not.

    Your platter just has two thumb holes in it, right? No big open gaps like shown below? (Pic courtesy of OrganDonorParts)

    [​IMG]

    That's a Yamaha P-350 belt drive platter. It should physically fit more or less, but not really work properly.


    The only other thing I can think of is if all screws and mounts are tight, then maybe the ball bearing of the spindle has been significantly worn down to the point where the platter loses that needed height to prevent rubbing. The ball of the bearing rides in that round thing in the middle of your motor, here:

    [​IMG]

    It's a very small clearance between the platter and the chassis. If a prior owner repeatedly ran it with something heavy there (record weight comes to mind). It could have prematurely worn down the bearing.

    [​IMG]

    If that's the case, and you feel it's worth it to fix, that motor is still available on organ donor. You already see it's only a few screws holding it on, the only additional step would be to solder a few leads. That module would replace the spindle and bearing, along with the whole motor.

    But, the flip side is that there's a possibility that it may make no difference at all - and that's a tough call.

    Let me have a look at my 751 again and see how tough it is to check that bearing.

    I'll log back in here in a while. But like I said, don't give up yet. I'm sure it's still fixable.
     
  6. Tcomisky

    Tcomisky AK Subscriber Subscriber

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    Hi, how about a grinding sound coming from a Yamaha YP-B4? I picked it up yesterday and the seller assumed it was motor mounts causing the noise, I've taken it apart and looked, it does not appear to be the motor or the mounts. The sound appears to be coming from something rubbing on the large plastic/teflon R-Gear or the actual main shaft itself?
    It almost sounds like a low clicking sound, like a baseball card in bicycle spokes?
    I'm thinking maybe it needs silicone grease (does white lithium grease work well on these?)?

    The sound goes away when the platter and belt is removed, I can also similate it by spinning the platter by hand with the belt removed, so that elimates the actual motor from the equation.

    When I turn the main shaft by hand, when it's free from the r-gear assembly, it sounds like the issue is with it.
    I can hear something odd with it. Here it is in the first photo. I assume I need to take off this metal bracket to remove the shaft and see what's in there? So, before I do, what IS inside there? Lol is it a single ball that it rides on? What should I use to grease it if I get it all apart?

    Thanks.
    Tom


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    Here is the top view of the main shaft:


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  7. Tcomisky

    Tcomisky AK Subscriber Subscriber

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    Nope, no bearing in there that can be accessed, but now that it's removed, it doesn't seem to spin with any issues, although it does have up and down play in it..

    I cleaned up all the old grease that was on the gears and will re-grease it all tomorrow and see what happens.

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  8. reydelaplaya

    reydelaplaya AK Subscriber Subscriber

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    Wow, you got that out of there pretty quick! LOL I'm still not sure what would be causing the sound you describe. But if you can't hear it on just the spindle and bearing by itself, there's a good chance it's coming from one of those plastic tracks/gears like you mentioned.

    The spindle sits in a pocket and rides on a single lubricated bearing, usually a ball. The up/down play you have is probably normal as long as it's not excessive. As for lubricant, there is stuff called bearing grease that you can get at an auto parts store, though I believe others, including myself, have used a light machine oil with success.
     
  9. reydelaplaya

    reydelaplaya AK Subscriber Subscriber

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    I've got an idea.

    If you have access to a caliper gauge,
    [​IMG]
    you could measure from the back of the bearing cup to the top of the spindle and ask the folks at Organ Donor if they would do the same on the motor they have. If theirs is longer by a mm or so, it may be your best bet to get theirs, because if so, it could signify that your bearing is indeed worn significantly enough to cause rubbing. I'm certain they'd be happy to do that if you explain why.

    I'll probably have a chance to pull mine back apart here tomorrow afternoon to see how tough it is to disassemble that motor and get at the bearing.

    I'll post pics and let you know. :thumbsup:
     

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