pureangst

A Solution To Blankdisc And Recording Problems.

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Good evening gentlemen!

If you're in the rather tricky position of losing recording ability on your MD unit, your warrantee's run out, and you're out of luck paying for an extravagent overhaul by sony tech, I might have the solution for you.

Although this is my first post, I've been a lurker of these forums for quite some time after buying my first MD unit (R700) a year and a half ago. During this time I've ran through a R900, and now currently using a N1.

Recently a friend of mine lost recording capability on his N1 imported from japan. Since it was an import, sony tech started playing games with respect to how much they'd charge to get the unit fixed (in Toronto any way). So he turned to me for help.

From what I've seen on these forums, this recording problem always crops up from time to time, and at first I was jaded by the number of complaints in the absence of any sort of helpful info, aside from the lazy lines, "bring it back to get it serviced". Please!

The following guide describes how I managed to fix an N1 with the supposedly common "recording" or "blankdisc" problem. I will not guarentee anything; this article is intended as a final option to an otherwise broken MD.

~~~

Notes before we begin:

1. This is intended as a last resort attempt to correct recording problems. You will be making irreversable 'adjustments' to your unit.

2. You will need a certain basic competancy in electronics; ie: be able to spot a broken wire, and not be intimidated by some basic basic soldering. Knowing common vocabulary also helps

3. You will need to take your MD apart, which necessarily voids your warranty. Do this at your own risk!

4. You must work methodically as well as have a sharp eye for details when dissecting your MD. If you cannot take apart your MD and put it back together, don't read further.

5. Find a pair of non-working headphones (that are headed for the trash) or buy the most inexpensive headphones at a local dollar store (we will be using the wires from them).

6. Patience. Don't be surprised if you find it doesn't work perfectly the first time (took me two weeks off and on).

7. Read this over before you attempt anything. Visualize the flow of work and make sure you know what you're doing before picking up that soldering iron!

~~~

Abstract:

(for people who know what their MD looks like internally, and want to get to the point)

The ribbon cable that services the magnetic write head of the N1 is prone to breaking, as the magnetic head is coupled to the optical head (so even playback will stress the cable). The solution is to bypass the broken ribbon cable with wires, allowing signals to once again reach the write head.

The key aspect is the choice of wire used for the bypass; it must be extremely thin and very flexible, to reduce contributing any mechanical resistence to the lateral movement of the read/write heads as they traverse the disc surface. Single conductor wires will not do the job as they offer too much resistence, preventing the read/write heads from traversing the entire range from the inner to the outer edge of a disc. Use the wire scavenged/scuttled from inexpensive earphones for this task, as they are very thin multi conductor wires with a fibre core, and also insulated via coating [?].

~~~

We will begin with a diagnosis of your problem.

I'm working with the N1 for simplicity and knowledge sake (as I've fixed only the N1 so far).

1. Functional Unit:

Is your MD able to play recorded discs?

If not then you've got bigger problems that I can't solve.

2. Make sure it is a problem with recording:

Is your unit able to record via microphone input? (as opposed to problems transferring if using NetMD software).

If so, you're having software problems, which is not my focus in this thread.

If not, read on!

3. Cleaning:

Some times problems can be resolved by cleaning the optical head.

Use a cotton swap and some cleaning fluid (not water!). Personally I used rubbing alcohol as it works well with fingerprints and dust. I hope others will correct me or suggest alternatives if you're well acquainted with cleaning solutions.

Test to see if the problem persists.

4a. Dissection:

Download the service manual for your MD model (if you can) and follow the diagrams to remove the outer shell of the unit.

For most Sony models, the casing is a two piece design; the bottom segment covers the circuitry board and battery, while the top consists of the operative buttons while serving to protect the recording head.

Following the service manual steps should let you take apart the casing easily. Remember for the N1 (and similar), the battery cover must go first, then the bottom casing, then the top.

Note: 'Open' the MD (as in popping it open like you were going to insert a disc), remove battery cover, then remove bottom casing.

You should see a ribbon cable that runs from the top casing connected to the circuit board via a special 'connector'. Remove the screws securing the top casing, and flip it over so you can see the inside of the MD, while keeping the ribbon cable attached.

The ribbon cable is anchored to the board via a flat 'connector'. The 'connector' is a two piece construct; you can release the cable by pulling softly on the two sides of the connector segment facing the ribbon. Do not, do not tug on the ribbon cable itself. If you find the ribbon difficult to detach, it means you havn't released the connector yet. Don't go any further if you can't pass this step, undo everything and take it to the sony dealer.

Sony's portable MD recorder designs are relatively universal.

You should be able to identify the optical lens head, attached to the motors and the axle that allows it to track the disc. This (to the best of my knowledge) is similar to a cd player optical head, so no surprises. The optical head is on the 'bottom' of the unit, and stays horizontal even when you open the case for inserting discs.

You should also notice the magnetic write head, attached to a metal arm that is fixed to the 'top' of the interior chasis, which can move up and down to accomodate insertion of discs.

Take care in not touching the metal arm or the magnetic write head.

4b. Test

Reattach the battery clip, and insert the gumstick battery. Close battery cover to secure battery. Your view of your opened MD should be birds-eye, with the chasis popped up as if accepting a disc.

Insert a disc with content in it. Preferably a full disc. Make sure it is write protected.

Instead of pushing down on the left chasis arm to 'load the disc', you can detach the left chasis arm (by pulling it gently to the left farther), and let the chasis , along with the disc, drop into the loaded position. Get something to keep the right chasis arm down (as it activates a switch that tells the unit the cover is closed, allowing you to turn it on).

You should be able to turn on and play the disc using the controls on the top casing, while being able to see the disc spin and the magnetic head track across the disc surface. Pay attention to how high it floats above the disc (vertical distance)

Stop the player, and remove whatever you used to close the right chasis arm switch (let the arm lift up). The unit should turn off by now as it thinks you opened the case to pop a disc out. The disc itself won't pop out as you've released the left chasis arm that helps lift the disc out. You must lift the chasis yourself and remove the disc.

Replace with an empty or expendable disc, and once again load it (using steps above). Try to record to the disc (you don't need any input), while paying close attention to the magnetic write head. Make detailed observations regarding the vertical distance of the head relative to the disc. You will need to refer to it further on. It is closer to the disc surface when you are recording than when you are in playback.

Eject the disc once again, and remove the battery, detaching the ribbon cable from the top casing, put the top casing somewhere safe.

5. Identifying the source of the problem:

At this point the problem should be apparent. There is a ribbon cable that connects the magnetic read head, runs through the flexible metal arm, and traces a path to the circuit board on the bottom, where it is soldered at two points to the board. This cable is easily broken, and this should be your problem, if you find a broken cable.

If you've got keen eyesight you should also notice that the magnetic write head has only two leads (wires)!, and also the magnetic head + arm construct is intimately connected to the optical head/block, so that the magnetic head moves in unison with the optical head.

Since the magnetic head is coupled (intimately attached) with the optical head, the ribbon cable servicing the magnetic head is always under use, even when you're not recording anything (ie: during simple playback). This is the exact problem.

At this point it is obvious what steps must be taken to fix the problem.

Simply bypass the broken ribbon cable and you should be fine, right?

6. The broken cable:

At first I tried using liquid solder (comes in a pen, you can 'draw' solder lines with it) to patch up the ribbon cable, but it doesn't work well.

It seems the ribbon cable consists of a paper-like 'base' or substrate, with very thin copper wire (they're flat so i'm supposing that these wires are printed onto the substrate) deposited on top, finally covered with a protective and flexible polymer/plastic. I must admit it is an elegent design, as well as a major pain to replace.

This is the toughest step; replacing the ribbon cable.

You must find wiring that is very very thin, yet very flexible and pliable.

Even the smallest gauge wires you can find in 'surplus' stores will not do the job. Do not use single conductor insulated wires (wires with only a single copper wire insulated with plastic), even if they are extremely thin, as they are not flexible enough to do the job (yes they may feel very flexible in your hands however). The motor mechanism that drives the motion of the optical/magnetic head (not the disc motor) is very sensitive to resistance; it is so sensitive that single conductor wires will provide enough mechanical resistance to prevent the heads from moving/tracking far at all (more on this later).

I has taken me a month of trial and error before realizing the best wires for the job are the multi conductor wires within cheap headphones work best for this situation.

Most cheap earphones (using the earbud types as an example) have two wires originating from the stereo plug, one wire for each ear. Cut the plug off, and split the two wires. You only need a wire length equivalent to the distance covered by the original ribbon cable, so save the rest for other odd jobs i suppose (don't forget to leave a little margin, in case). Strip the wires and you should see that each 'wire' servicing the earbuds actually consist of two very thin and fragile wires, each wrapped around a fiber core. Generally the copper wires are 'ground' and the coloured wires (red and blue) carry the signal. You can use any of them; I decided to go with the red and blue just for simplicity in wiring.

Prepare the wires by applying very very little amuont of solder to one end.

I suggest dipping the end in flux, then melt the solder so it flows onto the wire.

Very little solder is needed. You don't want the solder to 'weight down' the magnetic head.

7. Bypassing the ribbon cable:

Attaching wires to existing ribbon cable is a difficult process and can be 'hit and miss' as the printed wiring beneath the plastic sheath is rather thin. You might just burn through the ribbon too.

Here's another tricky part:

Make a detailed note of the vertical position the metal arm is when at rest (floating above the optical head). Chances are you will bend the arm out of the original shape when you're working with it. The arm must be at a certain position in order to be able to record. Too close to the disc and you will scratch it. Too far from the disc surface and you will lose recording ability.

Carefully detach the metal arm that carries the magnetic head from the rest of the MD by removing the single screw that secures it. It will be difficult as it is also glued down. Take your time and be careful, using a fitting screwdriver (I used a flat head rather than the philips (cross) as flat heads don't strip the thread as easily - your preference) and making sure you don't strip the screw.

Remember the shape of the arm!

Once you've detached the arm, look at the bottom side. You will see two relatively large solder points where the magnetic write head is wired to the ribbon cable. I soldered the two headphone wires to these points (existing solder at these points should be enough to accomodate the wires). Make sure you don't create a short circuit (check for solder bridging). Secure the soldered wires by threading them though the holes of the metal arm (don't worry, the ribbon cable is useless to you now).

Let the wires trail same path the ribbon cable used to take. They should be long enough to allow the read/write heads to reach the outer edge of a disc, but not too long that it gets cluttered up when the read/write heads return to the inner areas of a disc, as clutter will cause resistance and that will hamper read/write head movement.

Cut any excess wire, and prepare and solder the other end to the points on the circuit board where the ribbon cable was anchored. Take note of which wire solders to which point from tracing the paths taken by each wire within the ribbon cable. (this is simple, you shouldn't mix it up at all given only two wires!)

Reform the original shape of the metal arm (if you've bent it, which you should have avoided), and reattach the arm back to the MD. Make sure it is not skewed (should be perfectly in line) and tightly screwed back in as you don't want any misalignment. Check the vertical distance of the arm to make sure it is floating at the same height as it was before you detached it. This is crucial.

8. Testing:

Your MD should be fixed by now, but we want to make sure.

Reattach the ribbon cable of the top casing (the casing with the play/rec controls), but keep the cover loose (don't screw it in). Be careful not to break this ribbon cable (haha!)

Reinsert the gumstick battery. Close battery cover to secure battery.

Your view of your opened MD should be birds-eye, with the chasis popped up as if accepting a disc.

Insert a disc with content in it. Preferably a full disc. Make sure it is write protected.

You should be able to turn on and play the disc using the controls on the top casing, while being able to see the disc spin and the magnetic head track across the disc surface. Try playing some tracks now, especially try to play track 1 (close to inner area of disc), then jumping straight to the last song (which should be at the outer edge of the disc, assuming you didn't move any tracks). You should have no problems with the read/write heads tracking from inner to outer edge of the disc. If you do, it means your wires are causing too much resistence (which means you're using too thick wires! redo it with thinner, more flexible wires).

Stop the player, and replace with an empty or expendable disc, and once again load it (using steps above). Now test by recording from mic-in. Keen observers will notice the magnetic write head arm will be lowered closer to the surface of the disc when recording. Play back to see if you've managed to record anything. If not, retrace your prior soldering and wiring steps and see if you missed any details.

At this point, the most critical detail (aside from obvious wiring connectivity mistakes), is the vertical distance the magnetic head floats above the disc when recording. Make sure it lies the same vertical distance from the disc surface when recording as it did during your initial test before the bypass.

Once you've managed to get it to record and playback audio from the mic-in, you've sucessfully repaired your MD!

9. Reassembling

Remove the discs, and reclip the left chasis arm with the chasis.

Secure the top casing first, making sure you don't crush your new wires.

Remove the battery and the battery cover, so you can reattach the bottom casing. Take care when reattaching the bottom casing, as you've got to fit the hold switch on the bottom face as well as the 'open' switch (to open the shell for discs). You won't be able to fit the bottom casing snugly without being able to fit the hold and open switches as well.

Reattach battery cover and put back all the screws you took out (should be 9 screws in total).

Power the unit up and do one more recording test on it using mic-in, then try downloading songs through the cradle.

Done!

I hope this long article will help those of you out there stuck with a broken recorder.

Good luck!

Update:

The N1 I fixed a week back lost recording ability once again after spending a long, hot day in my backpack while I was out hiking. You may run into intermittent problems when the MD has experienced a temperature change.

I solved this issue by reopening the top cover and gently pushing the flexible write head arm down towads the optical head several times ("flexing" it), so it would acheive tighter floating distance to the disc when recording, and problem was solved! Note that in order to push it down, you've got to have the chasis 'lowered', so detach the left chasis arm first, or else the metal construct that holds the MD disc will prevent the write head from behing pushed down; you need to flex it so that it can almost touch the optical head. You don't need to flex too much, a slight 1/4 mm adjustment is enough. When you're done flexing, just make sure the head isn't scratching the disc by testing recording while the top cover is still removed, but with ribbon cable still attached so you can control the unit)

As an aside, if you've read through the service manuals for most sony units, there's a section on temperature calibration in service mode. I believe that serves the same purpose; namely to reposition the vertical distance of the write head when temperature change affects the metal arm. Interesting stuff!

Update #2:

Mag. Write-head must be in contact with the disc surface.

To avoid skipping issues when recording, clean both sides of the disc.

You may also want to quickly wipe the bottom 'contact surface' of the mag.head as well, with a cotton tip, as I've found grime buildup there that lifted the mag.head, hence no contact. Be careful though!

Update #3:

Ressurecting an old post, if you have problems where the unit blanks the disc and makes it unreadable (and hence unformattable by sonicstage), there is a dirty hack to manually format the disc. Don't do this if you have no idea how to navigate service mode or understand the implications of a mis-executed hack.

So far, I know it works on my N1, and has been reported to work on the N710.

1. Get into service mode:

set (hold) on; hold down (vol -); >, >, <, <, >, <, >, <, (pause), (pause).

2. access [AUTOCOM 500] using (vol +), enter using (play).

3. access [510 ACCESS] using (play).

4. starting at [511 xxSCC], move to [518 xxS03] using (>).

5. change S03 to S00 using (vol +/-), so the value reads [518 xxS00].

6. press (stop) to execute.

7. disc mechanism should be heard rattling.

8. exit service mode by removing power.

voila, the corrupted disc should be blanked.

info thanks to leorick

original post here

Edited by pureangst

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This is definitely sticky material. Thank you very much for your contribution.

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I got my minidisk for my birthday and it as worked since then put i have had my computer fixed so i had to reinstall sonicstange 1.5 and now when i try to get a song on it says "an error has occurred while converting the data" i have tryed about 50 differenet songs and it keeps saying the same thing plz help me :ninja:

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Most likely your problem is that you didn't do a proper uninstall-install of sonicstage, as converting songs is a software issue, not a hardware issue.

There's plenty of info around here that tells you exactly what to remove when doing a complete uninstall; just check the stickies in teh netMD forum.

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I have the exact, exact problem with this stup*d unit... OMG it is pissing me off.. SONY SHOULD do a recall... can we have an offical petition?

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I sent sony this email.. hopefully i will hear from them

Hi, i would like to inform Sony of a common problem with their NetMD Model MZ-N1... many have indicated a fault in the product, specifically the recording head, and/or the connections associated with it. Here is a link to a forum which discusses the problem: http://forums.minidisc.org/viewtopic.php?t=4712. This will help further explain my problem.

Here is an exert: "Abstract:

(for people who know what their MD looks like internally, and want to get to the point)

The ribbon cable that services the magnetic write head of the N1 is prone to breaking, as the magnetic head is coupled to the optical head (so even playback will stress the cable). The solution is to bypass the broken ribbon cable with wires, allowing signals to once again reach the write head.

The key aspect is the choice of wire used for the bypass; it must be extremely thin and very flexible, to reduce contributing any mechanical resistence to the lateral movement of the read/write heads as they traverse the disc surface. Single conductor wires will not do the job as they offer too much resistence, preventing the read/write heads from traversing the entire range from the inner to the outer edge of a disc. Use the wire scavenged/scuttled from inexpensive earphones for this task, as they are very thin multi conductor wires with a fibre core, and also insulated via coating"

I believe this problem is not a "case-specific" scenario due to improper usage, but a fault in the design and/or construction of the MZ-N1 unit.

My ultimate goal is to bring this problem to the attention of SONY and i hope they will further investigate it. Hopefully Sony will realize the problem with the MZ-N1 and perform a recall as many people are out of the warrenty period, including myself.

Thank you for your time and i hope to hear from someone.

-Wilson

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Well,

I write this little tutorial up as a last resort for others who have problems with their units and have no alternatives left to explore.

If your MD is under warrantee, then by all means send it back.

When you have exhausted all reasonable means of solving this problem, then read my solution and do it yourself.

There's no point in telling Sony that you're angry about their workmanship and are proceeding to do some ad hoc repairs by following some instructions you found on some site. Please!

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Hi

An excellent article! Do you know whether this problem also effect's the N10? (i think the internal hardware is the same???)

Thanks

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Mazuio, thank you for the links. I have changed your links to ones translated by babelfish so that people who speak English can somewhat understand it.

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You have done an incredible job of writing a very good article about replacing the ribbon cable with wires.

In it you make a statement about the magnetic head riding above the minidisc a certain distance from the disc during record. In my MZ R55 this head rides right ON the disc during record. As there is no optical function to the magnetic record function side of the disc, there is no harm in scratching it. I have 2 or 3 discs that function perfectly with some minor scratches on them. Maybe Sony redesigned this part of the machine in later models but the closer the magnetic record head is to the disc, the more effective its signal is on the laser input to the disc.

Thanks,

Mason

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You have done an incredible job of writing a very good article about replacing the ribbon cable with wires. 

In it you make a statement about the magnetic head riding above the minidisc a certain distance from the disc during record.  In my MZ R55 this head rides right ON the disc during record.  As there is no optical function to the magnetic record function side of the disc, there is no harm in scratching it.  I have 2 or 3 discs that function perfectly with some minor scratches on them.  Maybe Sony redesigned this part of the machine in later models but the closer the magnetic record head is to the disc, the more effective its signal is on the laser input to the disc.

Thanks,

Mason

Yes, it's the same sort of situation for my N1; however I'm not worried about scratching the top surface of my discs (since data is read out from the bottom), I'm more worried about damaging the fragile mag. write head. Anyway, I do concur that the write head is positioned nearly in contact with the disc during writing. thanks for the input though!

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Hi,

Thanks to this post i've been able to diagnose why my damn N1 won't record anymore! So i've pulled it apart and sure thing it's the broken ribon cable.

BUT before i go about replacing it i do have a question i need to ask... Does the replacement wires need to be insulated?? I've looked at those tiny multi-cored wires as used in earphones wrapped around the fibre core but they don't appear to have any insulating qualities (other than the thick black plastic on the outside which would prevent the magnetic head from moving to much wouldn't it)? Wouldn't the two wires short together or short on the metal chassis if i just solder them up without any insulation on the outside of them?

Sorry, maybe i just missed something basic here??

Thanks!

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Very good observation.

From my experience, I did not find the wires short out.

Thus far my fixed N1 has not given me trouble, and it has been nearly a year.

If you are really worried about possible short, I would suggest you spray them with a thin coat of something insulating. Hairspray? Teflon? Silicone Lube? I have no idea but I bet there's plenty of products out there.

One thing is for sure, you have to use thin wires.

There is no substitute.

Best of luck!

Wouldn't the two wires short together or short on the metal chassis if i just solder them up without any insulation on the outside of them?

Sorry, maybe i just missed something basic here??

Thanks!

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Hi again,

Thanks for that. I actually realised after some research that those thin wires used in earphones do already have an insulating coating on them... that's the coloured coating on the wires - the red and green stuff! I just scraped some of that coloured substance off the ends of the wires to solder them on. Its just plain copper wire under that. So YES, they are perfectly safe to use as is without any additional insulation. My N1 worked fine after that except the wires were initially too short and they prevented the head mechanism from reaching the end of the disc! DOH...

Thanks again!!

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Problems Re: Skipping & Blankdisc (when write-head cable is perfectly fine)

I've recently been having problems with skipping when recording. Pretty weird as it occurs seemingly at random positions on different discs. At first I suspected dirty discs but after rigorous cleaning, the problem persisted.

Anyway, as usual I opened up my N1 and checked for anything weird. I became worried when my unit was blanking discs and I lost recording capabilities, even with the ribbon cables intact. Very interesting!

Well, after a few days working at it, I finally figured out what may be the problem:

My magnetic write head was not in contact with the disc surface when writing, hence no data was written to disc. In conclusion, for proper writing capabilities;

the write head must be in contact with the disc surface.

By extension, make sure you clean both sides of the disc if you're running into skipping issues. You may also want to quickly wipe the bottom 'contact surface' of the mag head as well, with a cotton tip, as I've found grime buildup there that lifted the mag.head, hence no contact. Be careful!

Oh yeah, very light contact between write-head and disc surface is enough.

Edited by pureangst

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Hi.

I tried to enter service mode on my n910, it didnt work with the manual to 710 but with a manual to 510, which you can see above. Thanks a lot.

Is there someone, who knows this service mode on 910? I have problem with DC adapter

(I have already made a topic)- when I want to charge it is showing PC->->MD sign, although I press STOP. I think it is some stupid software error and could be repaired through service mode. Does anybody have some idea? Reset or something like this? Thanks, David

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Hi girls/guys.

First; I apologize for posting in an already (?) dead thread.

Secondly; impressing work there, pureangst!

My problem:

my 3 year old MZ-N1 has just recently decided not to record anymore. (It plays fine). This holds for both recording via the PC (Net Simple Burner and other software) and also via 'rec sync' (optical cabel). Well, in fact, it records approx 2 minutes of the first tune, then silence..

So, I cleaned the lenses - no effect. Then I took the MD apart as described above; no (visualy) broken ribbon cables. The only thing I haven't tried yet is new discs.

The MD has already (under warranty) been repaired once, I will try argueing that this also should be coverd under the warranty. To be honest; this must have been the most shitty pice of HW I ever have bought..

Anyone have a clue on this ? Any help is highly appreciated.

best regards,

Holiday.

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Just got word from the repairshop.

The recording laserhead was broken, approx cost to fix is norwegian kroner 1.300 (USD 200). I dont think it's worth it, even if it plays ok thoug.

They wouldn't even concider a repair under the warranty, mainly because the player 'looked used'. Imagine that..

Well, I think I leave Sony in favor for a MP3 player (less moving parts that can break) huh.gif

Best Regards,

Holiday.

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This might fit in - maybe it doesn't.

Anyway, a two year old MZ-N707 which is having some problems with recording. It will record just fine, but when I go to play the information back through a Comrex Vector (using stereo mini cable) I have been getting "blankdisc". This is a new problem. Did I somehow screw up a setting or is this thing potentially shorting out from the Vector?

Any help would be greatly appreciated as I am losing material and interviews daily and don't want to buy a new one!

Thanks,

Loren

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Well, 'blank disc' was my problem also. The recording process looked ok, but any attempt to playback resulted in a 'blank disc' message.

Looks like your recordinglaser is dead/about to die.

Best regards,

Holiday

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Problems Re: Skipping & Blankdisc (when write-head cable is perfectly fine)

I've recently been having problems with skipping when recording. Pretty weird as it occurs seemingly at random positions on different discs. At first I suspected dirty discs but after rigorous cleaning, the problem persisted.

Anyway, as usual I opened up my N1 and checked for anything weird. I became worried when my unit was blanking discs and I lost recording capabilities, even with the ribbon cables intact. Very interesting!

Well, after a few days working at it, I finally figured out what may be the problem:

My magnetic write head was not in contact with the disc surface when writing, hence no data was written to disc. In conclusion, for proper writing capabilities;

the write head must be in contact with the disc surface.

By extension, make sure you clean both sides of the disc if you're running into skipping issues. You may also want to quickly wipe the bottom 'contact surface' of the mag head as well, with a cotton tip, as I've found grime buildup there that lifted the mag.head, hence no contact. Be careful!

Oh yeah, very light contact between write-head and disc surface is enough.

Wait, so what do I do if the ribbon is not damaged in any way? My mz-r700 was getting the blankdisc error, so I opened it up. I got it to record a minidisc while still open, so I could see what the little recording arm is doing. It's not coming anywhere near the disc when recording. It's about a fifth of an inch away. How can I get it to write on the disc? Thanks

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Yes, it's the same sort of situation for my N1; however I'm not worried about scratching the top surface of my discs (since data is read out from the bottom), I'm more worried about damaging the fragile mag. write head. Anyway, I do concur that the write head is positioned nearly in contact with the disc during writing. thanks for the input though!

Not only does the record head ride nearly on top of the disc, it rides ON the disc. Check R37, R50, R55, R700, R900, N707, N410, etc, etc. I've been repairing these things for months now, and if the record head doesn't ride on the disc surface itself, you WILL have problems recording. I found a tiny spec of what looked like styrofoam on one of my repairs and removing it restored the recording function. I am going to get an N1 in for repair for exactly the same problem as is described here, and I will apply the excellent repair suggestions enumerated above and see what happens. Most of the MDs I work on the record head tape is soldered to the main board. Sometimes the foils are broken at the solder pad, which is easily repaired. The rest of the assembly is very robust, particularly the record head, and unless the user stuffs a screwdriver into the load area, doesn't need much attention.

If you have a pair of Optivisors 8x you can then really determine that the record head is designed as a sort of sled itself, with flutes in it to keep dirt from sticking to it. Also, using the same techniques to observe the disc rotating while recording or playing, you will always notice some runout between the disk and the heads. There is no way you can adjust a clearance tolerance between the record head and the disc to accommodate for that. The head has to ride on the disk, period.

Read up on the Magneto Optical recording techniques to corroborate this.

Thanks,

Mason

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Wait, so what do I do if the ribbon is not damaged in any way? My mz-r700 was getting the blankdisc error, so I opened it up. I got it to record a minidisc while still open, so I could see what the little recording arm is doing. It's not coming anywhere near the disc when recording. It's about a fifth of an inch away. How can I get it to write on the disc? Thanks

First, you can't get the record head to lower while the lid is open. But, if you took the lid off and tried to get it to work, you need to actuate 3 switches to get anything to happen, then you might possibly see whether the record head does indeed touch the disk. There is a motor and gear train that is responsible for lowering the head while in record mode, but the only way to make sure it all works is to take it lid off and turn the gear train by hand. There isn't any way that it won't go all the way down, so it would have to be a mechanical obstruction in the gear train or lid lockdown mechanism. Otherwise, the electronics are at fault. If you know your way around the Sony calibration and test routine in the player, you can determine where in the system the problem is.

Jacques

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Hi Pureangst and All!

Thank you very much for the comprehensive description of a wire-repair!

I had this damn BLANKDISC problem for quite long and no-one could make me the repair, except sony-services. They wanted of course to change the whole head for lot of bucks...

Despite the fact, I have no big experience in soldering that little electronic stuff, I decided to make the repair myself.

The operation was a success for the first sight.

(If anyone is interested, I could post an url with the photos.)

My BIG problem is the following:

After repairing the MD, I am able to record via the line-in (sp, lp2, lp4), but at usb transfer the following happens:

The song appears on the disc, but only with 0 or 1 sec length. The transfer process is also very fast, it seems that no transfer is made, only TOC Edit writes the songs title on the disc.

Does anyone have an idea? I tried to write with OpenMG JukeBox and SonicStage also. Same result.

Is it an issue of the patching (wire too infelxibel, too much impedance, too far from the disc) or is this probably another defective (probably expensive) part?

So I patched my "BLANKDISC" error and found a "NO USB TRANSFER" error.

Thank you very much in advance and again for the good description!

Regards!

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