Minidisc Repairman Q&A #4

David Popovits
Sigma D.O. Electronics
3, Sheinkin str. Tel Aviv, Israel
Tel. 972-3-6290339
Fax. 972-3-6203579
([email protected])

August 2000

These questions from readers on these 1 2 3 4 5 6 7 8 pages followed David's original article about portable MD recorder repair

  1. Question Hi David First, I'd like to say that I enjoyed reading your recent postings to It is good to see Israel has found its place on the Minidisc scene on the net! I have been a Minidisc enthusiast since my first machine: A 1995 sony MZ-R3. since than I have added to my collection an MZ-R50, MZ-R55 and recently a MDS-JE330 (deck). All the four are in good working condition! And now for my question: I wanted to record the soundtracks of a couple of music DVD's that I have using the optical digital output from my DVP-S325 (guess the brand...) Of course I set the audio mode of the DVD player to linear PCM (48khz), plugged the right cable but was not able to record digitally. the deck displayed "cannot copy" and all the three portables displayed "NO COPY". It is clear to me that the machines had no problem with the 48khz sample frequency since all of them include sampling-rate converters, and indeed I could hear the music from the headphone connected to the portables, the D/A stage worked fine. I guess this is an SCMS issue, but I thought it was intended to prevent second-generation digital copying, which is clearly not the case here: why can't I make digital copies of original DVD's soundtracks that I have? Does DVD's soundtracks carry the digital no-copy signal? Is there any way to circumvent SCMS in this case? Thanks in advance, Eli Leibowitz, Israel

    Answer Hi Eli, The status block transmitted from the disc you want to record contains data, describing the disc and the copy generation status. In your case the disc is described as CD (copy of original) with copy protection asserted, and no digital recording permitted. It does not mean that you have a non-original disc, it means that is was recorded so as not to allow even 1st generation digital recording. To overcome this situation visit portal, you can find many solutions to bypass this problem. Truly yours,

  2. Question Hello David, I have an MZ-R55 with a NH-9WM battery (!). The machine doesn't seem to charge the battery very well. It goes for about 5-10 before it runs flat (play back, volume moderate). I am using a replacement power supply I sourced to recharge the battery. On the DMM (Digital voltage meter) it measures 3.01VDC. To be sure I checked in the power supply and it had an LM317T regulator and voltage adjust resistor (forgot the value), along with filtering components. It is a very well made supply. The current limit of the supply is 800ma. Although the battery charges for 3 hours, it still won't play for long. Any suggestions? Mabye I need a new battery. Nearly forgot to add: I don't use the remote stick on my machine, as it had a fight with my boot and the boot won (I didn't see it had rolled off the desk, and I trod upon it!). Anyway, I'm not going to replace it, way too expensive!. Is there a way of using small rectangular or SMD leds to backlight the display using a signal somewhere from the recorder that either goes low (tie anode of led to +3vdc via limiting resistor) or high (tie cathode of led to gnd with limiting resistor). I know I could permenantly backlight during recording, using the red led's +ve signal to drive the backlight, but that is useless to me - I normally record in well lit situations, and this would only be a current drain. What I want is a 5-6 second backlight coming on whenever a button is pressed. (except stop/charge). Thanks again, Ben

    Answer HI Ben To make the unit play longer, use the NH14-WM bat. It has longer life then the NH9, it is usually supplied with the MZ-R55. Regarding your back-light problem question. I wouldn't try to force a solution that involves introducing of new parts into the MD, or making any other internal modifications. Stay away from it and be happy as long as it still works. The MZ-R55 tends to make problems even without digging inside of it. If you must have light, use an external source or buy yourself an Aiwa MD with back-light. Truly yours

  3. Question Hello David, I feel very grateful to have discovered your fine article on Minidisc servicing on the website. And for your generosity of spirit to share some of your knowledge and understanding of these most complex little units with 1000's of Minidisc users! I've been using a Sony MZ-R55 for about 6 months, and I take good care of it, and it has served me well. Recently, however, the left channel of my earbuds have been cutting out. When I physically press the jack in and hold it in, everything is fine. Because I am a Broadcast Engineer I have had a considerable amount of experience working with electronic hardware. I suspect the reason the left channel is cutting out, is because the tip of the 3.5mm jack has somehow been bent back towards the rear of the unit from continued use- (part of the 3 pin + 3.5mm jack, that also takes the remote control accessory (which I never use because I hate the poor design of it!) So my hope was I could remove the bottom cover, and gently move the tip of the jack towards the front a few mm, put it back together, and once again be back in the saddle again! So I removed the 5 tiny machine screws (1 mm or something?) holding the bottom shell, and gently got 3 of the four sides to move up 3/16" or so...but the side on the right remained tight. David, can you tell me how to correctly proceed with this project? Do you concur with my analysis? Have you experienced this malfunction in your work? Any light that you can shine on this problem will be so very much appreciated! Kindest regards, Ken Horton, Santa Monica, Ca.

    Answer Hi Ken, Thanks for your compliments. Regarding your problem. It is a well known problem. It can happen after the MD falls, or gets a mechanical shock to the earphone plug. If you are using the remote control plug the situation is better because the pressure on the earphone socket is lower. If you are not using the remote control plug you must check the earphone plug carefully before connecting it to the MD. If it is not perfectly round it can push the spring loaded contacts inside the socket more than it should. Even if you use good plugs it may happen that the connection of the socket with the printed circuit board becomes loose. All these things can cause the problem you described. In order to fix it you will have to resolder well all the contacts of the earphone socket to the circuit and carefully move the contacts toward the center of the socket. Check carefully that the printed circuit is not broken. If the situation does not improve you may have to replace the earphone socket. How to remove the bottom cover ?

    1. Remove the 5 screws (as you did)
    2. Open the battery cover and move it aside 90 degrees
    3. Lift the cover from the side opposite the side where the 3 external sockets are mounted. If you cannot lift, use a dull knife to release the pressure and continue to lift from the same side all the way until the cover is off.
    4. If the back side of the bottom cover (the part with the power socket) is not moving (as a result of extra force maybe because of falling) you will have to use the dull knife to help its moving. Be careful not to damage the external battery connector and the yellow cover of the power socket. From my experience, humidity or liquids can create a sticky cover which is very hard to remove.
    Truly yours,

    Followup Hi David, I want to thank you for taking the time to make such a thoughtful and timely response to my e-mail about the headphone jack problem on my R55! I will try again, using your instruction, to get the bottom cover off and proceed! Perhaps I will e-mail or phone you sometime soon. Kindest regards,

    Followup #2 Hi Again David, The problem with my R55 headphone connection is now fixed! It was a hairline crack in the jack tip solder point to the board. Thank you again so much for your excellent help! Cordially, Ken Horton Santa Monica, Ca.

  4. Question David, In your original posting to and in your responses to questions, you have mentioned several times that you feel the Sony MZ-R50 is the best portable recorder. Could you elaborate? Thanks, Lee

    Answer Hi Lee, Good question, difficult answer. When one says something is the best it is very easy to see that it is from his own point of view. In this sense, what is the best for me may not be the best for you. I'll try to answer.

    The best machine for anybody depends on what he is expecting from it. If you are looking for the smallest unit, it is not the case of the MZ-R50. The Sharp MD-MT831, Sony MZ-R55/70/90/91 and other MD's are smaller. If you care for long play time with the battery it is not the case of MZ-R50; the others mentioned are better. If you need a reliable MD, one that will not break easily, with relatively high volume, a machine that doesn't suffer from all kinds of problems, stable with 40 sec. antishock mechanism choose the MZ-R50. I repair all kind of MD's daily, it is the only machine that is brought for repair due to age (normal) or a dramatic event (falling into the sea...) and not because of 'funny' symptoms which show that the MD's were brought to the market unfinished, or because of small events that created large problems.

    Sharp MD's series 7XX: Almost all of them that come for repair have the UTOC ERROR problem. It is the most amazing thing I see daily. You own a new Sharp MD, you don't drop it, you use high quality discs, original power supply, in room temperature and one morning the display shows UTOC ERROR. The user manual says in those cases that the disc is bad or not clean and other funny jokes. Then you take the disc and place it in another MD and every thing is fine. So, how can we even consider to buy such an MD?

    Sony MZ-R55: A small machine. It looks nice but nothing more. Press stop and in many cases it will start recording. Leave a recorded, unprotected, disc inside the MD during charging and you may find the disc was erased. Drop the machine from a few inches and it will stop recording completely. Use a non-exact power source and it will die partially or completely. Press a bit too hard on the keys and the whole cover will bend. How can we take such a creature seriously?

    Sony MZ-R70/90/91: Beautiful MD's. All of them tend not to identify protected/unprotected disc. They all make internal loud and funny noises. Due to the special modus operandi the spindle motor is stoping very often (to save power) nobody told him that he must continue to revolve. I repair many of those that just stop with no prior alarm, usually at the high portion of the disc.

    I can continue with Aiwa MD's having the 'CAUTION' announcement, similar to the UTOC ERROR, or the Sharp with the lever problem but let's go back to the MZ-R50. Looking on it with the MD Book of History you can see that it is based on older models of Sony. They learned the materia gradually. The 50 looks like the 30 and the 35 but it is better. They introduced a new laser unit and they built the MD from high quality materials. The covers are made from magnesium and the disc holder from titanium. It has the same weight as the MZ-R30 but is much smaller. It came out so well that Sony used the same mechanism for the MZ-R37 and for the MZ-R5ST. They used the same laser unit for the MZ-R55 but here it tends to break quickly, not as with the older brothers.

    You see Lee it is not easy to explain. According to the gestalt theory the whole is more then the sum of its components, hold the MZ-R50 in your hand and you will understand what I'm talking about. Truly yours

    Followup David, Thanks for the informative response! I only wish the MZ-R50 was still available new . . . Lee

  5. Question Hi David, I read your wonderful MD repair articles and questions posted on I have a question not related to the player as to the disc. I recorded a friend's band on my Sony MZ-R90, and it all worked fine. That's until I accidently erased the whole disc (!!!!). Do you know if it's possible to recover the disc, to unerase it? Thanks Peter Australia

    Answer Hi Peter, As for now the MD format is not supporting unerase feature. I believe that in the future it will be possible in the same way it is done with our computers. This site gives some tips that may fix your problem: Truly yours

  6. Question Hi, my name is Xingxia and I just read the information you put on the Minidisc Community Page. I find it very interesting for someone to be nice enough to answer all people's problems with their precious MD. I also have a little problem with my MZ-R90 which I got few months ago. It was playing fine at first, but then sometimes it pauses own its own for like 2 seconds and continues playing again. It doesn't pause such as when you press pause and the little disc thing flashes, it pauses and everything stops. I take very good care of my MD, my MD isn't slightly bent, I don't press the main unit, I use the remote, I don't jump around with it, so I don't know what the problem is. It has a 40 sec anti-shock, but it sounds like it's skipping even if I sit it down on my table. It used to be about 0 pauses per disc, then 2-3, then 10-15. Could you give me some advise. I didn' think it was a big problem until I read your QA#3 sheet question number 5, where the pauses eventually became stutters. Please help me. I don't have any repair shops around me.... thank you very much.. Truly yours, Xingxia Zhang

    Answer Hi, Thanks for your compliments. As for your MZ-R90, what you experience is not a normal behavior of an MD. I found the same problem with an MZ-R91 (same as MZ-R90). It was completely new and behaved exactly as you describe. I cleaned it well (although it was not dirty), I made readjustment in test mode, lubricated it but all I can say is that it is a problem that was born with the MD. Something in the electrical or mechanical design is wrong. I found that the problem is more severe when using the external PSU. When running on its battery the situation is not so bad. One of our clients reported to me the same fact. If you are still under warranty go to the shop and try to get another machine. Truly yours,

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