An expert who has achieved level 2 by getting 100 points
An expert that got 5 achievements.
An expert whose answer got voted for 20 times.
An expert who has written 20 answers of more than 400 characters.
Re: unstable speed
In a direct drive turntable, the platter sits directly on the motor shaft.
This motor shaft is the spindle, and as far as I know, the 'bearings' are pressed inside the motor, or on the top cover of the motor.
(It is probably the brass colored ring at the bottom of the spindle.)
If quartz lock is on, the motor is probably the cause of the problem.
a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need. goodluck!
- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
The platter on the JVC LA-10 does not come off as most turntable platters do. It is attached to the spindle with a Philips head screw.
Here are the steps:
Remove dust cover from turntable. Unscrew hinges and lift.
00.jpg" alt="Remove dustcover at hinges.">Remove dustcover at hinges.
Secure tonearm to prevent stylus damage.
00.jpg" alt="Secure the tonearm.">Secure the tonearm.
Remove slipmat from platter.
00.jpg" alt="Remove slipmat.">Remove slipmat.
Turn the turntable on its side and remove screws that hold the top to its base. Remove platter by unscrewing the bottom plate from the turntable. The spindle bearing is held in place with a Philips head screw. Loosen it and the platter will separate easily from the spindle.
00.jpg" alt="Separate the spindle from the platter by loosening with a Philips head screwdriver.">Separate the spindle from the platter by loosening with a Philips head screwdriver.
When you removed the platter were there a couple of brass or copper washers around the spindle? If not you could try and find a couple to lift platter. Also check for wobble in the platter new ones can be had. There are clubs you may have to join on facebook that will help you one is Vintage HiFi and stereo mostly a bragging site but very helpful with links to others. that is where I found help with my Pioneer turn tables, also Ebay is where I found parts bought a PL518 sold for parts to fix the two I had.
Spindle test. Actually finding out if the spindle motor is spinning the Spindle, at the maximum spindle speed in RPM's, the spindle is rated to spin at, (At maximum spin up) Also a few other quick tests.
Basic construction of your harddrive. IDE (PATA) or SATA;
Inside the harddrive's case are;
1) Platters: They resemble CD or DVD disks, and are usually made of metal, or glass.
The Platters are coated with a magnetic medium. (Ferrous substance. Think Iron ) There may be 3 to 6 Platters, or more, inside the harddrive case. They are coated on both sides with the magnetic medium.
2) Spindle, and Spindle Motor: The Spindle is part of the Spindle Motor. It is the shaft of the motor. Comes out of the Spindle Motor, and the Platters are attached to it.
The Spindle Motor is designed to spin the Spindle (Shaft) certain Revolutions Per Minute, when called upon. The maximum RPM's it will spin is stated for the harddrive unit.
Older harddrives were rated at 5400RPM. (Slower before the above time period) Newer harddrives usually spin up to 7200RPM. Gamer type harddrives may spin 10,000 or 15,000 RPM's.
3) Read/Write Head: The magnetic medium on the Platters, is arranged by a Read/Write Head. There is a Read/Write Head above, and below, every Platter inside the Harddrive.
The name indicates what the Read/Write Head does. When the Read portion of the head is activated, it reads what is ON the Platter. When the Write portion is activated, it writes TO the Platter.
(The magnetic medium is arranged, by the Write portion of the Read/Write Head. It is arranged in a series of 0's and 1's. 0 being OFF, 1 being ON. This is changed into Machine Language the computer can use )
4) Actuator Arm: The Read/Write Heads are attached to an Actuator Arm. The arm swings the heads back, and forth, across the Platter's surface. (When called upon it can swing the Read/Write Heads back, and forth, at HUNDREDS OF TIMES A SECOND. -> HUNDREDS )
5) The Actuator Arms are attached to an Actuator Motor.
The entire assembly above is encased in a.....case. It is assembled in a Clean Room. A room that is 99.9 percent dust free. The outfits the assembly technicians have to wear resemble a NASA space suit. They have to walk through an air corridor, and be b-lown off by air jets, before they can enter the Clean Room.
The harddrive's case has a small filter on it. This helps keep the atmosphere inside the harddrive, as it is outside the harddrive, but with NO moisture, NO dust.
On the bottom of the Harddrive case is an electronic circuit board. Controls the hardware inside the harddrive case, and is connected to the motherboard.
The Spindle test is to see; 1) If there is any axial, or horizontal runout. That is to say if the Spindle wobbles, so to speak. If so the Spindle Motor bearings are bad.
[Platters have to stay Dead Level. The Read/Write Head is spaced off of the Platter, by about .00003 of an Inch. (3 hundred-thousandths) May be closer my figures could be off, In comparison an average human hair is .003 of an Inch thick. (3 Thousandths)
Due to the speed the Platters spin at, and the closeness of the Read/Write head to the Platter, the Read/Write Heads actually float on a cushion of air, when the harddrive is active.
When you hear or read the term 'Head Crash', it means one, or more of the Read/Write Heads, has touched a Platter, (Or Platters), and wiped off some of the magnetic medium ]
2) Spin up speed. How long it takes the Spindle Motor to spin up to the required RPM's. Actually, how long it takes the Spindle Motor to spin up the Platters, to the desired RPM.
Doesn't reach the RPM goal? Spindle Motor bearings are probably bad. (Or a failure in the electronic circuit board, on the bottom of the Harddrive. Doubt it. Usually just fails altogether )
Remove mat from platter. Using a small screwdriver remove the cir-clip holding the platter on, careful here mind your eyes it may spring away. Carefully lift the platter of, not too much force, you will see the belt laying underneath. Take the belt and put it around the underside of the platter, you will see where it goes, just on the large inside edge. Put the platter back on but not the cir-clip yet. Move the platter around until you can see the motor spindle. Using a small screwdriver and your finger put the belt onto the motor spindle. Make sure it is not twisted. Test the player if the turntable spins OK replace the cir-clip, this can be tricky but get it located first then lift the back up to clear the spindle bearing. There you go.
The turntable or motor bearing may be gummed up, or the belt or drive tire may be slipping.
The turntable is usually held in place by an E-shaped spring clip right at the base of the spindle. Carefully spread it with a flat-blade screwdriver just enough to slide it out, but keep a hold on it with a finger because sometimes they will try to fly across the room. Once you have the clip off, you can lift the platter off to service the bearing. Wipe it clean with a soft rag and lubricate with a very light oil (sewing machine or clock oil will work).
Often the automatic drop mechanism will work poorly if the turntable has been sitting a long time. Sometimes the problem is the aforementioned sticky bearings, but occasionally it is necessary to clean and grease the sliding parts.
If the rubber drive component is slipping, you may be able to use rubber conditioner to restore it (supplied by MCM Electronics), otherwise you can get replacement belts from the same company.
There are a few ways to determine a lazy spindle motor.
listen to it. If it sounds like a diesel engine, with regular knocking sounds, bearings are failing... new motor
sit the unit on its side, see if it then reads...if bearings are worn, this reduces "slop"in the motor that can contribute jitter to the RF waveform. If it plays then,new motor
put a drop of oil into the top bearing of the motor. If it starts to read and run ok, then the bearing may be tight, and need lube, or the oil is acting as a hydraulic bearing. It will not fix the problem if it is a worn bearing. ...new motor.
if it spins up slow, and with screeching noise, the bearings are tight. see below for a solution.
Some other solutions.,
disconnect the connections to the motor remove a top mounting screw from the motor, and use a straw to flood the motor with crc 2-26, and spin up for 5 minutes one direction at 12 volts, then the other direction. Cleans the armature and brushes.
I always use a steel ruler to measure the height of the platter to the deck of the transport. then set the spindle height for the new motor up to the same as I measured. Happy to answer and questions that you may have. I have repaired literally hundreds of cd players over the years... including many NADs Cant recall just what the 501 has. But spindle motors cause a lot of problems with cd players.
Your Garrard Type A is most likely an idler-drive deck (With a rubber wheel driving the turntable).
- Under the rubber mat there's a "C" shaped clamp to be found around the spindle. Remove that and keep safe. Now remove the platter and behold the 'guts' of the monster. On the left you should see a thick rubber wheel with a metal core inside, directly under that wheel you'll find a 3 step pulley protruding from under the frame.
Plug in the AC and turn on. Carefully look at the pulley. It should spin fast. If not, immediately unplug the power otherwise you'll burn out the motor. If the pulley spins too slow, the specially inserted factory grease/oil may have "set" or dried out during the silent years..
The same goes for the grease/ oil which is inserted in the spindle-bus. We'll get there later.
- Make sure the AC is OFF! High Voltage Inside!
- Lift the frame from its casing/ plinth and make sure it's completely supported when upside down, so you don't damage the arm!
- Locate the BIG motor! :-)
- The lower bearing screws may be 'glued' on with red lacquer. (Shellac) (This was done to prevent repairs by users (Warranty Expiration)
- Unscrew those and lift off the bearing. (a light tap with a small mallet may break the lacquer and make it easier to unscrew. DON'T TRY to unscrew forcefully as the screws may get damaged! They're made of brass I thought. )
- Clean it out with a tissue or a non-pilling piece of cloth. The Top bearing can be found under the motor-pulley which is fastened with 3 small screws. (Note! This bearing doesn't need greasing 'cause it's only there for support!)
Once cleaned out insert the tiniest little amount of Singer-Oil (Sowing Machine Oil) into the LOWER bearing. and put it back over the motor shaft. Screw the bearing back on. Make sure the screws are not too tight as, once again you may damage the heads. There! You just re-greased your turntable motor!
Next: If the speed selector lever is hard to move. Apply a small dab of vaseline onto the frame right next to the lever. Gently move it to and fro a few times and that's that.
- Spindle Bus:
This is somewhat more risky because this is practically what makes the turntable! The spindle was inserted in the factory by pressure, oil first, spindle second, forcing all the air out, leaving a film of oil around the spindle-shaft..
- Locate the cast-iron spindle-bus. Almost on top there you'll see a screw somewhere (again sealed with the red shellac)
- Gently try to loosen it. AGAIN: Do NOT use excessive force!
After unscrewing keep it safe.
- Turn the upside down frame over again to its normal position.
- Gently try to lift the spindle out of its bus. DON'T YANK IT as this piece of stainless steel was crafted with extremely high precision! Then again, the vacuum won't let ya, heheh.
- Degrease with a non-pilling cloth or tissue drenched in thinner/ pure alcohol. Use a pencil and non-pilling cloth to clean out and degrease the spindle bus. Never use tissues as these may tear leaving residue in the spindle bus which decreases performance!
- Now poor some Singer-Oil onto the spindle and a small drop in the spindle-bus. Slowly rotate it between your fingers so the oil can distribute itself all over the spindle.
-Put the spindle back in its bus and let it sink in under its own weight (Get some coffee. Watch the Superbowl, Take a vacation, cause this may take a while!) DO NOT force it in as you may damage either the bus or the spindle!
- Make sure the idler wheel is smooth and round! Run your fingers along the inside of the platter to see if there's any residual rubber left behind. If so, you're gonna need a new wheel sometime soon. If not, congrats! Make sure the idler wheel is free from grease, oil dust and dirt and that it runs smooth! Make sure the inside of the platter is also free from dust, dirt, grease or oil to obtain maximum grip or friction.
- Join turntable back together with spindle and give it a soft spin. (Oil warms up inside spindle bus)
Check the spindle height. The platters sometimes slip down the shaft, or the spindle motor bearing drops and the platter gets closer to the lens.
check that the spindle motor has not become lazy and "poling". give it a few spins. then try to read a disc again.
Clean the laser lens with a cotton wool bud moist with windex glass cleaner. Then "polish the lens with a dry one.
the spindle motor top bearing is worn and the payer mistracks as the armature moves about under the changing drive conditions. Makes the player mistrack and skip. More likely to happen at the start of a disc, because the disc is spinning fastest whilst reading the TOC.
A drop of light machine oil from a syringe oiler can help the bearing to spin an not produce the knock. Only a short term fix to give the motor a "lube". Once the oil leaches out of the worn bearing the problem will return. I have run motors immersed in an oil bath to rejuvenate them before... but better to replace it anyway if its suss at all. Good luck, You could bump my profile by giving me a "FixYa" rating for my sharing my "knowhow". Any problems check back with me here.