Minidisc Repairman Q&A #6

David Popovits
Sigma D.O. Electronics
3, Sheinkin str. Tel Aviv, Israel
Tel. 972-3-6290339
Fax. 972-3-6203579

August 2000

Note: For Sony Equipment Problems you can also call Sony's National Direct Response Center at 800-222-7669

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: Short battery life on MZ-R70
    I just read your comments on the Sony MZ-R50 and it made me envy everyone who currently has one.... I originally bought one in 1998, but it broke a year was quite durable, tho! It survived falls on brick paths, hardwood floors, ceramic tile floors, and even a cement patio! However, after the patio, it fell on a rug, which must have thrown off the magnetic record head. The thing stopped recording properly. I did, however, purchase a return warranty, so I went back to the store, only to discover that they were not selling electronics anymore! I was forced to ship it to Warrentech in Texas, who replaced my beloved R50 with an R70. It's small and the color is cool, but, do I put this?, IT STINKS!!!!! It's loud, it has an incredibly short battery life, the remote left me longing for my good ol' stick-type, and so on...... Jeff

    Answer Hi Jeffrey, A small remark regarding your MZ-R70. You may replace the original NIMH which has capacity of 700mAH with one with capacity of 1300mAH. It will almost double the time of usage. It is not expensive and can be found in many shops. Truly yours,

  2. Question: Aiwa AM-F65 won't read discs
    Hi there, I have a problem with my Aiwa AM-F65 Minidisc player. The error message is saying TOC read, then making a funny noise as if the disc is getting stuck, then the message changes to CAUTION and then it cuts out. Can you help? I have tried pressing the reset at the back but that has not worked and I am at a loss. Tracey

    Answer Hi Tracey, "CAUTION" on Aiwa MD's means that the unit cannot read the disc. To solve the problem try the following.

    1. Replace disc (I'm sure you did)
    2. Use a cleaning disc to clean the laser unit.
    3. With the door open look for objects that shouldn't be in the unit near the laser unit and the motor, (hair, matches, loosen screws...). If you find such, remove them carefully.
    If this will not help you will have to take it to a repair shop. You may need to replace the laser unit. Truly yours,

  3. Question: Home replacement of Overwrite Head doesn't fix Sony MDS-302 record problem
    Hi , Please excuse my intrusion. I have just finished reading your responses/article on with respect to repairing MD Decks/Portables. I hope you can help me clarify something and possibly assist me. A little under 5 years ago I bought a Sony MDS-302 Minidisc Recorder from the UK (I was living there at the time). The unit worked wonderfully - no complaints. About 2 years later I had an accident with it, a disk got locked in the mechanism, and upon getting it out the "overwrite head" snapped. I ordered a replacement part from Sony Service (UK) and fitted the part myself - everything worked fine again. I now live in Trinidad, W.I. and I brought the MDS-302 with me where it has been working fine for the past year, however recently it stopped recording/updating the TOC. Originally I thought there was a problem with the disks themselves (TDK Color) as they worked fine in my MZ-R3. However upon closer inspection I noticed the "overwrite head" was bent, of course upon trying to straighten it, it snapped, so I ordered a replacement from Sony Service (UK). The part I received was different in design - I was relieved as this part seemed more sturdy, I noted on the packaging that the part is for the MDS-S35 but am assured the mech's in these decks are the same (?) both by Sony (UK) and reviews from I fitted the part - but the problem persists, I contacted Sony Service (UK) who told me the "overwrite head" needs setting up with a scope, when I explained that I had already replaced one of these parts, I was told it was "just luck" that it had worked. Can you help/advise on this? Any help you can give would be greatly appreciated - thank you.

    Answer Hi MR. X, Next time please state your name. I would like to know whom am I trying to help. As for the recording head: Many components take part in the recording process. One of them is the recording head. If it is broken or misplaced you cannot record. It is true that the best way to calibrate and to fine tune it is by using an oscilloscope. On the other hand if the mechanical parts to which the recording head were attached have not been bent nor suffered a change of shape, then when you connect a new recording head it will record the first time you try it. It may need some fine tuning but it will work for sure -- unless you have another problem in the recording circuits. The recording head is driven by a 'bridge' of 4 transistors and the transistors are driven by an IC. There is a relatively high voltage in this circuit. All those components must be OK in order to record. In addition the laser output should be high enough to perform the process. Truly yours,

  4. Question: Will a broken LCD leak liquid?
    Hi there, Having read your series on, I thought I might add my problem to the mix. My MZ-R91 recently developed a cracked LCD due to a slightly bent lid (how, I don't know as I treat it with kid gloves, but hey, that's life!). All I want to know is if there is a risk to the unit from the leaking liquid, or whether the LCD is completely sealed off from the rest of the unit. If not, can I take off the lid and remove it somehow? I would have gotten it repaired, but Sony gave me an estimate for 50% more than the unit cost me, so it wasn't worth the hassle. It still works, just the main unit LCD is dead, so I plan to use it as a player. Cheers, Majuran Manohasandra

    Answer Hi Majuran, The broken LCD can stay in the unit. Although it is called Liquid Crystal it doesn't behave like liquid in the sense you are talking about. I can sell you an LCD for your unit for USD120.- Truly yours,

  5. Question: Isolating a recording noise problem
    Nice to read all your questions and answers for Minidiscs. I am really impressed by your knowledge and experience. I recently bought Sony MSD-JE330 and found a problem using analog recording from CD to Minidisc. The recorded Minidisc always has an annoying buzz noise in the background when the music is quiet. I changed the unit's location and used an expensive connection cable, but still it did not help. I notice this noise is not coming from the CD player, the connection between the CD player and the MDS-JE330 is through a Yamaha R-V702 AV receiver. If I switch to CD, I can hear no noise, but if switch to Tape (include Minidisc), I can hear noise during recording. I have even tried a direct connection between the CD player and Minidisc deck but the noise still exists. The funny thing is, sometimes there is no noise during recording, but most of the time there is. I have sent it to a Sony Repair center, they replaced major parts but did not get rid of that noise. I read a message board and found that some others have the same problem I have. If this is a product defect, can it be repaired? If I use optical input, will it help? I have never used it because my CD player does not have optical output. James wang

    Answer Hi James, First you have to know what is causing the noise. Is it the recording circuit or the playback circuit? In order to make this test use a disc that was recorded on another MD unit, one that is not making noises. If everything is now quiet, it means you have problems in the recording circuit. If you still hear noise, try the earphone output. Is it quiet? If it is, connect your MD to your amplifier using this headphone output (volume should be relatively low on the MD as it feeds a line input). If in all cases you still hear noise I think you are in trouble. I don't know if it is a common problem but anyway it won't help you if it is. If there are no noises in the experiment you made then the problem is in the recording circuit. You must test it with an optical link. If it is not ok you will have to live with your MD unit as a player only or try to get a replacement at the shop you bought it, if it is still possible. If the recording made through the optical path is ok go to next step. Use an analog cable having an isolating audio transformer in series. If the noise is coming from ground loops you may improve the situation by using such a device. To all members of The steps mentioned here are good for all MD's having similar problems. Truly yours,

  6. Question: How to fix a broken MZ-R50 glass display cover?
    I have an MZ-R50 and an MZ-E90, and I must admit I like the 50 much more. The E90 is too slow and has bad shock protection. I've had my R50 for two years, and it has handled the knocks very well. Except one. In my very packed bag one day it was pressed hard against a metal bike lock. The unit worked strange for a while but fixed itself all of a sudden and now works perfectly. The problem is that the display is cracked. It still displays fine, only the glass is cracked. Is there any way to fix this without spending too much money?

    Answer Hi Dave, If the LCD is broken you cannot repair it. You must replace it and it is expensive. If only the transparent window covering the LCD is broken then you can remove the broken one and replace it with a peace of plastic of the same size, glued very carefully (so as not to glue up the whole MD). Truly yours,

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