Sony MDS JB980 high pitch noise

[Andrew12345]

I have a Sony JB980, when playing md's there is a high pitch noise.

When a disc is spinning I can hear a constant fast ticking noise, on some discs there is a high pitch squeeling noise on top of the ticking noise.

I successfully replaced the loading mechanism belt in August, but the noise did not start until October.

 

 

 

[kgallen]

Is this noise through the audio or a noise that can be heard from the unit?

[sfbp]

If it's coming from the unit, it might be a good idea to take the cover off the drive itself and observe the movements of the head when it's making these noises. Only if you feel reasonably technically competent. I'd hate for you to ruin a working machine.

One clue can be if the minidisc inserted is getting hot. That may be a sign the drive is out of alignment (or Laser Power maladjusted, or both).

Have you tried DISABLING the NetMD function by the switch on the front panel? If this is connected to PC's USB but the wrong driver (you may need the 64-bit driver since most Windows installs are 64-bits nowadays), it's just possible this is some weird artifact of the PC and the JB980 arguing over that USB cable.

[Andrew12345]

The noise is deifinitely from the drive itself, not the audio. Disabling NetMD has no effect.

The discs do not get hot. I will remove disc cover this weekend.

[kgallen]

Worth confirming if it’s play only or play and record (actually while recording not record pause).

I noticed this week that both of my MDS-E12 are ‘noisy’ with some discs during record. These are old discs I’ve had for many years and during record the overwrite head is in contact with the reverse of the disc. During play (laser only) they are silent. 

[Andrew12345]

The noise occurs during playing and recording, the high pitch squeeling noise is like the squeal of a car fan belt, but not as loud obviously. 

If I remove the drive cover and observe whilst playing, is this safe due to laser being used?

 

[kgallen]

Could be a dry bearing in the direct drive disc motor although I’ve never come across that before.

Have you tried other discs? I have noisy ones but probably not a squeal noise.

Re the laser, if there is a disc inserted and properly seated then the laser is under the disc (but pointing up). I’ll let you make your own assessment based on that.  Certainly never look anywhere near the laser if you enter service mode as the laser can be turned on with no disc in. 
The laser is in a lower power mode when playing. When recording the laser is in a high power mode that pulses on for each data bit to raise that tiny disc area above the Curie temperature whilst the overwrite head on the top sets the appropriate magnetic field depending on whether the data bit is a 1 or a 0.

[Andrew12345]

The high pitch noise occurs on half of my mds. I took the unit cover off and listened closely to the disc mechanism whilst playing. The noise comes from either the motor in the top right corner of the mecharism or the wheel that holds the disc. 

Does the motor in the top right corner drive the wheel that holds the disc, as I cannot see any cogs or belts, perhaps they are underneath.

Sounds like something needs a touch of silicone grease.

 

 

[kgallen]

Spindle motor is direct drive and is under the centre on the MD. The spindle motor is the only one that is spinning when playing a disc but there isn’t really anything you can get at to lubricate there. 
 

Edit: Top right is sled as NGY says, not load/eject as I initially said. 

[NGY]

9 hours ago, Andrew12345 said:

Does the motor in the top right corner drive the wheel that holds the disc, as I cannot see any cogs or belts, perhaps they are underneath.

That one is the sled motor. If the laser needs to do a lot of repositioning, you can observe its cog "oscillating" heavily. This can cause a noise. A short video could help us better assessing, what actually happens there.

[NGY]

10 hours ago, Andrew12345 said:

The high pitch noise occurs on half of my mds.

If you choose one good and one "noisy" MD, you can do a quick comparison. Observe the cogs by looking at the drive from behind (see photo below). The leftmost, smallest one would show the most visible "oscillation":

[Andrew12345]

I have attached a video. The disc is a TDK rxg, this has the ticking noise that I always get on all mds and the high pitch noise that is unbearable. 

nearly all of my mds are TDK rxg, about 70% of them end up emitting the high pitch noise after a short while of playing them, occasionally when the noise is really bad playing briefly stops then starts again.

you will notice I have put a bit of white silicone grease on the upper cogs

 

[NGY]

Thanks for the video.

I can hear both noises, the ticking one and the high pitch. The ticking sounds like coming from the sled motor's gear chain. It is visible, that the laser has very hard time to keep in the groove. The high pitch - most probably - is coming from the disc itself, sounds like a friction noise. You can hear this noise "slowing" as the disc spins down after you hit the stop button.

As for the first one, it definitely calls for some checks and fine adjustment. I can give you a checklist, what to begin with, but as Stephen already pointed out, if you feel 100% comfortable going into that depth technically. Based on the result of these checks, it is probable, that your traverse and focus mechanisms need readjusment, but then that will require special gear, such as a test jig and an oscilloscope as a bare minimum.

As for the second one, I lean toward the spindle having an issue. The magnetic hub might have "descended" a bit on the shaft, causing the disc touching the shell somewhere while spinning. Not that easy to prove or disprove. Nevertheless, a quick (and "dirty") check: cut a 10mm dia circle from self adhesive paper (printable label, for example), and stick it into the disc's metal hub. This will raise the disc just a bit, the magnet on the spindle will still grab it properly. Check if the noise changes. You may need a second one on top of the first. Maybe a third. If the noise changes audibly, then we are on the right path.

 

[Andrew12345]

Thanks for the detailed advice. I have cleared the high pitch noise, this was really only by chance. What I did was touch the spindle hub rim with a watch makers screwdriver and turned the spindle a bit, whilst being careful not to touch the laser or anything else electronic. I also put a thin strip of adhesive paper on the plastic rim of an md (this is the rim that sits on the spindle hub rim), the drive though was not able to read the disc so I quickly pressed eject. 

The high pitch noise has gone then, hopefully for a very long time. As for the ticking noise, this appears to be very tricky fix. I have had the deck for 13 years and the ticking noise could of been there for a few short years, I only notice this noise in between tracks, therefore it's not really a problem to me. The deck casing reduces half of the energy of the noise. As the laser is constantly trying to find the groove will this eventually fail the mechanism due to wear and tear?

I don't have an oscilliscope, only a multimeter. Perhaps I could adjust the laser traverse and focus mechanisms by trail and error or perhaps best left alone.

 

 

[NGY]

Glad to hear that you got at least halfway in clearing those noises.

 

1 hour ago, Andrew12345 said:

As the laser is constantly trying to find the groove will this eventually fail the mechanism due to wear and tear?

The mechanism will probably survive us all. It is more the OP that can fail, for the excess focusing/tracking efforts. Those very thin, flat copper springs that hold the focusing lens can lose their flexibility. Also, the laser diode itself can age faster. Playback is less of an issue (still counts though), recording is where the laser will have most of the extra load.

 

1 hour ago, Andrew12345 said:

I don't have an oscilliscope, only a multimeter. Perhaps I could adjust the laser traverse and focus mechanisms by trail and error or perhaps best left alone.

I am afraid, you cannot adjust the traverse settings with a DMM only, or by trial and error. There is a specific waveform you must literally see in order to properly adjust. You can try to check the error rates and adjust the focus bias according to the SM, just make sure you follow it word by word. It is kind of a pain job, as you may need multiple attempts and the process can take an hour or even more to complete. It may also happen, that the factory recommended settings cannot be achieved - a probable sign that the OP itself has already an issue.

 

 

 

[Andrew12345]

I have now found what the cause of the high pitch noise was, one end of a wire spring under the spindle was lose and touching the spindle rim, I clipped the wire spring end back under the plastic arm that should of been holding it. 

The ticking noise could be less now perhaps, see video.

I could try to adjust the focus bias using the SM, is there a risk I could make things far worse though, basically is it fool proof?

[NGY]

2 hours ago, Andrew12345 said:

I could try to adjust the focus bias using the SM, is there a risk I could make things far worse though, basically is it fool proof?

Before you adjust anything, first check the error levels. Error levels can indicate (without "turning any knobs") whether or not it is necessary to undergo the focus bias adjustment process. FB adjustment is not foolproof, it is rather tricky. Apologies if I created an expectation that this the "thing" that will solve the problem. Proper FB setting is necessary for the laser to operate optimally - this is true. However, all other adjustments (laser power, traverse, auto gain, etc.) must also be checked and done.