Hi Knew2This,
The sleeve bearing on the top of the spindle motor is also a failure point. Run the motor through about 100R with 3~5 VDC, enough so it spins at a low RPM. Rotate it slowly and you may hear it knocking at some point. It is bad if it does.
I generally replace the spindle motor when I replace the head. I just picked up a Denon DCD-1630G that still had a working KSS-150A in it. I replaced it with a KSS-210A (with brass sleeve bearings) and the motor is on order. Its an odd MDN style motor. The hole spacing is different than the normal motors. The existing motor does have worn bearings (no surprise). I also have to service the clamper as well as it is a pressure type. I wish I had a Denon conversion kit to magnetic clamp!
-Chris
The sleeve bearing on the top of the spindle motor is also a failure point. Run the motor through about 100R with 3~5 VDC, enough so it spins at a low RPM. Rotate it slowly and you may hear it knocking at some point. It is bad if it does.
I generally replace the spindle motor when I replace the head. I just picked up a Denon DCD-1630G that still had a working KSS-150A in it. I replaced it with a KSS-210A (with brass sleeve bearings) and the motor is on order. Its an odd MDN style motor. The hole spacing is different than the normal motors. The existing motor does have worn bearings (no surprise). I also have to service the clamper as well as it is a pressure type. I wish I had a Denon conversion kit to magnetic clamp!
-Chris
Where can one buy generic KSS-210A and KSS-240A with sintered bronze slider bushings?
I recently purchased several generic KSS-240A from high-rated Asian ebay sellers.
Good thing: They all work perfectly.
Bad thing: All of them have plastic slider bushings.
They required no adjustments at all. And they produce 1.1-1.2V P-P RF signals. Their eye patterns are clear and clean. And they play all of my discs. These pickups averaged $12 USD each. Some of the eBay seller photos showed pickups with bronze bushings. But nobody delivered me a pickup with bronze bushings. Next time I buy some I will ask the seller whether their pickups have bronze or plastic bushings.
While digging through my parts stash I discovered another generic KSS-240A that I bought 10 years ago. It does have bronze bushings and it also produces a perfect eye pattern. But it is clearly a generic unit not made by Sony.
I also checked some original Sony-made KSS-240A that were still in their original CD players. I was pleasantly surprised at how well they still worked. They were still producing >1V P-P RF. It seems that I have 3 vintage Sony CD players which need only new tray drive belts, cleaning, & inspection. Now I’ll have to make a garage sale excursion to find more of them for $3 each so that I’ll have a place to use my generic KSS-240A.
I recall those MDN motors too. Definitely not easy to replace with Mabuchi. Hole pattern and bushing diameter where the shaft comes out are both different.
-EB
I can't remember where I got them. They were not cheap.
I bought a pair of those MDN type motors, cost me about $30 US each landed. When you need them, you need them.
I bought a pair of those MDN type motors, cost me about $30 US each landed. When you need them, you need them.
Did Denon frequently use MDN spindle motors rather than the Mabuchi RF-310/RF-320 series?
When I was in the retail audio business (1980-1990) we sold a lot of Denon CD players. My favorite at that time was their DCD-1500II. But my memory is a bit foggy about the repairs needed by Denon CD players at that time. I do recall some failures of KSS-123A pickups in earlier Denon models. The cost of replacing a KSS-123A (when the machine was old enough to be out of warranty) led most customers to buy a new CD player rather than fixing their old unit.
-EB
Hi EB,
No, mostly the Mabuchi motors. I was surprised to he the "MDN" type motor.
The KSS-123A head tended to get sticky. Sony's fault. Yes, they were expensive. However the NEC head used in the OMS-5/7 was a lot more expensive. My cost was over $500 ... and I bought one for an OMS-7 the customer didn't want to fix. I still have that machine.
If you think that was bad, try the CDM-1 mechs from Philips. The ReVox and Studer machines were ignorantly expensive to repair, but I still had some takers and fixed them.
No, mostly the Mabuchi motors. I was surprised to he the "MDN" type motor.
The KSS-123A head tended to get sticky. Sony's fault. Yes, they were expensive. However the NEC head used in the OMS-5/7 was a lot more expensive. My cost was over $500 ... and I bought one for an OMS-7 the customer didn't want to fix. I still have that machine.
If you think that was bad, try the CDM-1 mechs from Philips. The ReVox and Studer machines were ignorantly expensive to repair, but I still had some takers and fixed them.
As I work through my vintage CD player collection I may discover at least one with a KSS-123A in it. If so I will definitely check the condition of the focus/tracking actuator.
BTW, I discovered that I have not one but two Phase Linear 9500 CD players. I haven't inspected either one of them closely yet but they are moving closer to my workbench.
PHASE LINEAR 9500 | 2xTDA1540D–SAA7030 | HLPL 030010 (Toshiba OPH-31)
-EB
Hi EB,
Cool. I have never seen a Phase Linear CD player. I don't think they sold too many up here.
Watch the focus search to see if it is smooth. Otherwise you might have to run the lens up and down yourself with a variable power supply direct to the focus coil. I have been able to repair a couple heads that had low laser hours on them. You have to desolder the actual coils, remove the rubber suspension to get the lens assy off, then you will see the pole it slides up and down on. Clean it and do not put anything on it. Then reassemble and pray for the best. Don't forget to clean the sleeve that runs on that pole. It is supposed to be perfectly dry. This can take a couple hours to do, so relax and enjoy the job.
I hope you don't need to fix the head, but I have had brand new ones that are sticky. Good luck if you do, it is possible to fix them.
-Chris
Cool. I have never seen a Phase Linear CD player. I don't think they sold too many up here.
Watch the focus search to see if it is smooth. Otherwise you might have to run the lens up and down yourself with a variable power supply direct to the focus coil. I have been able to repair a couple heads that had low laser hours on them. You have to desolder the actual coils, remove the rubber suspension to get the lens assy off, then you will see the pole it slides up and down on. Clean it and do not put anything on it. Then reassemble and pray for the best. Don't forget to clean the sleeve that runs on that pole. It is supposed to be perfectly dry. This can take a couple hours to do, so relax and enjoy the job.
I hope you don't need to fix the head, but I have had brand new ones that are sticky. Good luck if you do, it is possible to fix them.
-Chris
I received the replacement laser assembly. Brass bushing and all! It was replaced. Upon verification the unit was working, I went ahead and replaced some of the filtering capacitors and the inline signal capacitors with some better quality ones. I was most interested in replacing the capacitors associated with the higher voltages of the tube front end. After a day of running to burn in the capacitors and re-check voltages, I brought the unit upstairs to listen. Sounded good. After a dozen cd's the original symptom of not spinning up reappeared. LED seemed to be lit and appeared to be hunting for focus as expected. I tested the spindle motor with a very quick 9V battery to the + & - terminal, CW and CCW. At that point, the player would correcly load and play the CD. I could not reproduce the original problem. Closed up unit, upstairs into main system , worked for half a dozen CD plays. Then stopped. Opened up unit. No spin. Using a P/S with a 100ohm resistor in series, i am able to get the motor to spin either way when I bring the voltage up to ~ 6V. It will spin if helped initially at 2.1V. After these tests, of course the player is now loading and playing CD. I haven't come up with any direct evidence the motor is bad, but the circumstances wrt working after playing with it suggests the motor is at fault. Also, experience has shown me intermittant issues tend tobe mechanical induced. The unit is a mabuchi RF-310T-11400 D/V 5.9. Long shaft? The top of the CD spinnng top unit [sic] is about 17mm above the top of the base platform. Think I'll order a new motor, long shaft. Price for replacement is very inexpensive. Difficult to replace? thank you.
Replace the spindle motor.
This is a very common fault. Over the years I have replaced hundreds of CD player spindle motors.
The RF-310T variety is widely available and cheap. This motor is in current production from several Chinese manufacturers. In my experience the quality of these new motors is acceptable. There is no need to search for “new old stock.”
Shaft length is important: Too long will prevent the disc clamper from working. It is possible to shorten a longer shaft by using a Dremel tool with an abrasive cutoff wheel. Be careful not to let metal chips get into the motor.
Important: Carefully measure the platter height before taking apart the CD transport. Platter height tolerance is +/-0.5mm (or better). If too high or too low the optical pickup won’t be able to focus on the disc.
-EB
This is a very common fault. Over the years I have replaced hundreds of CD player spindle motors.
The RF-310T variety is widely available and cheap. This motor is in current production from several Chinese manufacturers. In my experience the quality of these new motors is acceptable. There is no need to search for “new old stock.”
Shaft length is important: Too long will prevent the disc clamper from working. It is possible to shorten a longer shaft by using a Dremel tool with an abrasive cutoff wheel. Be careful not to let metal chips get into the motor.
Important: Carefully measure the platter height before taking apart the CD transport. Platter height tolerance is +/-0.5mm (or better). If too high or too low the optical pickup won’t be able to focus on the disc.
-EB
FYI: “D/V” on the motor label indicates the nominal “design voltage” for the motor. “D/V 5.9” is the most popular and basically means it is a 6V motor.
You will occasionally see “D/V 4” or “D/V 9.” This means the motor is “nominally” rated at 4V or 9V. In my experience the 5.9 and 4 are interchangeable. Also the 5.9 and 9 are interchangeable.
Because these motors are servo-controlled, the servo system is able to compensate for different rated voltages as long as the difference isn’t too large.
The D/V 9 motors often turn up in DVD players. I have successfully replaced many of those with D/V 5.9 motors. No problems.
Motors with D/V 4 are often used for sled drive. In my experience a motor with D/V 5.9 will work to replace these.
-EB
You will occasionally see “D/V 4” or “D/V 9.” This means the motor is “nominally” rated at 4V or 9V. In my experience the 5.9 and 4 are interchangeable. Also the 5.9 and 9 are interchangeable.
Because these motors are servo-controlled, the servo system is able to compensate for different rated voltages as long as the difference isn’t too large.
The D/V 9 motors often turn up in DVD players. I have successfully replaced many of those with D/V 5.9 motors. No problems.
Motors with D/V 4 are often used for sled drive. In my experience a motor with D/V 5.9 will work to replace these.
-EB
Hi EB,
Typically the sled and disc motors are the same rating, only the shaft length is different.
We used to have issues with sled motors, but I think they drive them differently now and have not had an issue with the sled motor in many years. They did not change the motor, although Yamaha went through three motor designs on their earlier CD players, the Carver DTL-50, 100 and 200 were Yamaha transports.
Hi Knew2This,
Like your screen name - LOL!
Yes, classic disc (spindle) motor failure mode. Just replace it now to save you the grief. It can be very intermittent but may just stop one day. Because you probably have a dead pole, it will cause digital errors and degrade sound quality even though the disc is spinning.
-Chris
Typically the sled and disc motors are the same rating, only the shaft length is different.
We used to have issues with sled motors, but I think they drive them differently now and have not had an issue with the sled motor in many years. They did not change the motor, although Yamaha went through three motor designs on their earlier CD players, the Carver DTL-50, 100 and 200 were Yamaha transports.
Hi Knew2This,
Like your screen name - LOL!
Yes, classic disc (spindle) motor failure mode. Just replace it now to save you the grief. It can be very intermittent but may just stop one day. Because you probably have a dead pole, it will cause digital errors and degrade sound quality even though the disc is spinning.
-Chris