Repair: Teac MD-H500i 

A Minidisc player is usually made up of separate modules, as is the Teac MD-H500i.
Although they require little maintenance, sometimes things can break. In this case it is simply old age, the lens can no longer read the discs and spits them out after a minute. No error message on the display and nothing crazy to hear. Time to take a look inside.

July 21, 2019 

A Mini Disc or Mini Disk (in Dutch) is a completely different story for me. It is digital and very similar to the CD. It also took me a while to really get into it, as I write this my experience with Minidiscs is almost zero...

But, here it is. The TEAC MD-H500i minidisc recorder in all its glory,
at least almost.

In the picture it looks like he's playing normally, but he actually skips almost continuously.
There's something wrong with it, I have no idea what. The person I bought it from could tell me he worked for shipping. Let's see what happened to it.

Wait a second! Before I show you this thing naked I must point out that the content contains electrically tinted images. It is advisable to follow my advice only if you have sufficient knowledge and work safely. I am also not liable for any mistakes you make if you follow my steps.

All right, it's going to be quite a story, so sit down and enjoy it.

Required tools:

  • Phillips screwdrivers PH0(0) PH1 & PH2
  • Griptang (of surgeontang)
  • Tweezers
  • Cotton swab or lint-free cloth
  • Container for screws
    (preferably several)
  • magnifying glass for visually impaired
  • a whole new lens...

A large part of the recorder is empty, made up of a few separate modules. It is, after all, a 'modern' device. I also repaired one with a different problem so I already had an idea of ​​the inside.

The problem occurs in this player when reading and playing the Minidiscs, so I suspect it is already in the reader of the CD.

I can easily detach the device that reads the CDs from the whole. This makes the work easier, but the amount of printed circuit board that I find does not make the job more fun.
You can easily detach the 'flat cables', no screws or clamps.

I have to admit, I've been tinkering with it before, but only made it worse, A Minidisc is now stuck inside and the gearing is out of time
(gears are not in the right position anymore).

Before that I had offered it to a HiFi shop for repair. Without success and I was €25 lighter. They also couldn't tell what was going on with it, they wanted to replace the unit shown above but it was no longer available.

A week or two went by and I wanted to get him to talk anyway.
I started searching the internet for all the information I could find about this machine.

No success, at least for the first few days.

I read in an article about a typical ailment with Minidisc players. Though I thought it wouldn't work, I gave it a try:

Without any problem, the recorder plays the Minidisc. No 'skips' or not being able to read the CD. I didn't see this coming.

As it turns out, most Minidisc players and recorders have components of for example Nylon, after a good number of years those parts weaken and gravity starts to play on them, if you put it on its side, gravity has no effect on it and plays without any problems.

I then searched hard for this so-called nylon spring, but could not find one, yet my recorder has a solution for what seems to be the same problem, I finally decided to look for a new lens...

But now first on with where we had stayed.

The Minidisc holder contains many parts. These can often only be released in one way. I've given them a (nick)name that fits.

We start by unscrewing the top plate, it is fixed with 5 screws below that we see the bracket and the bottom plate.

We are going to loosen the Bracket first.

You can clearly see that something is sticking through the Bracket. If I'm not mistaken this is the recording head. This is mounted on top of the laser arm.

First we loosen the spring that is attached to the Bracket, I use my locking pliers for this.

If we want to remove the metal bracket,
we can choose to squeeze it out (which I did).
Or you can already unscrew the recording head. Keep in mind that it is still attached to two wires, which you can carefully loosen at the other end.

You can squeeze in between them, provided you lift the recording head with tweezers, it is built for flexibility, but make sure that the head itself stays in place (don't touch it). He can shoot loose, you can see him hanging down.

You can also unscrew it beforehand, as you can see I did this much later. It should come off in no time if you are going to replace the laser. Put him away neatly.

On the left side of the device (when facing the opening). Sit the Conductor. This maneuvers the elements when you insert or remove a Minidisc.

Once again, loosen the spring that is on the left here, you can leave it attached to the Guide.

You can easily unscrew it with a sharp cross head (PH1)

The bottom plate now comes off easily, no screws to loosen, just carefully remove. On the left, the white arm jumps out a bit when you lift it, that's okay.

Since this is my second attempt, of course I still have a Minidisc in it. this one is released after I lift the metal plate, October 25, 1999. That's almost 20 years ago now!

I'm now wondering if the whole description above was necessary, now that I realize I replaced the laser mainly from the underside.

The Minidisc was stuck in this case so I had to, but maybe you don't even have to follow the steps above. Oops... Sorry!

To the right of us you see the bottom, there are still some cables attached to it, 3 to be precise, but one is at the bottom. For now, unscrew the 3 screws with a sharp Phillips head. Be careful not to damage the circuit board. 

With the screws out you can view the bottom, here you see this transparent 'flat cable'.
Only disconnect the other two cables first, the white one is easy, but the red/black of the recording head has to be removed with pliers or your nails.

By the way, I put the screws separately, there are too many congeners in the same container, I don't want them to get confused.

The transparent cable is clicked into place, the edges of the coupling on the printed circuit board can be extended. Do this again carefully because you will tear it to pieces. Only then can you disconnect the cable and put the circuit board away, carefully of course.

The colorful stripes you see here obviously have a meaning, the device that I'm taking apart here has gone through no less than 4 inspections!

This means that the device must not have been cheap. Usually you have to make do with a sticker that sometimes has the date on it.

We are now in the second layer, the second round.
Here you see 4 striking screws, you can loosen them with a cross head.

See the entire collection here. Despite the fact that it is a lot of work and there are many parts to disassemble, it is not that difficult. You just have to go through a few layers.

I also looked for (digital) manuals, but I couldn't find them. so it is playful learning here.

Let it be a coincidence that I have a box with no less than two brand new lenses!

I tossed the lens arm model number through well-known sales websites and had a hit. They also don't cost that much. 

I have a label circled in red "ISO 9001". This is a standard, well known in the business world. Translated it is 'say what you do' 'do what you say' and 'prove it'. At least the oversimplified version. I don't like that statement, but I see it often. I don't know the other label.

When we put the lens arms side by side, we see the resemblance. If you click on the left photo you can read a serial number. KMS 260B. This is the type number.

They are built modularly, so you can add external parts to them. The old lens has a few extra parts. The recording head must also be placed on the new lens arm again later.

Of course I had to remove the lens first, you can click on the photos. On the left you see the screws under which the ends of the shafts rest. They used two different screws for this. One smaller than the other.

If you manage to get it loose, you can free the lens arm. Do this carefully, you don't want to damage anything.

The old one has a metal plate on top (two even). these are secured with a very small screw. I was able to get it loose with a Phillips head PH00. This is one of the parts that needs to be transferred, it is an important component, it allows the lens to move back and forth.

There is also one on the new lens, but it has a very different shape. It is also secured with a plastic cap instead of a screw. The cable is clicked in the same way as the end we have already removed. so carefully slide it open.

We place the new lens in the place of the old one and check that it makes good contact with the third axis, which has a screw thread with which it moves the lens when rotated. You can see him here on the right.

The metal strip I transferred should rest on this. I slide the lens over the other two axes and screw the screws back in.

If the lens is properly attached, the recording head can be put back on, you can also wait with this until the other components are on, which might have been more convenient.

I rebuild the device as I broke it down. the metal support goes back on, followed by the other printed circuit board, but first connect all the cables, the transparent one at the bottom, the white one at the top, you slide those back in without much effort by the way.

If you have already placed the recording head back, you can click it back in, I do this with tweezers. You can neatly tuck the wire into a slot in the metal support.

Once you have secured the printed circuit board with its 3 screws, the metal bottom plate can be put back on. push the plastic arm down and back in.

Replacing the Guide is not so easy.
It's hard for me to get it into place, I think that's because with me the cogs are of time. If it is stuck again, don't forget to put the spring back in place.

Put the bracket back on, and beware of the recording head if it is already on, otherwise put it on afterwards.

Don't forget the spring on the back of the bracket!

Now the device looks like on a previously shown photo, that is what it is.

I put it back in the machine and try a CD, no luck...
The motor that revs up the Minidisc now won't turn! I can hear the lens moving. Could this be due to the new lens or did I not connect a cable properly?

I replace the old lens, and yes, the Minidisc motor works again....
Time to contact the supplier of the new lens.

Here we look through two magnifying glasses and a zoomed-in camera lens, the diamonds in the background are one square centimeter. The seller tells me that there is a soldering tip on the PCB to prevent the lens from being damaged by static electricity.

So I would have to break the soldering tip that I point to with the pencil with my soldering iron! The circuit board also looks different I see now, but the electrical circuit is almost the same.

We are now a few days further, the de-soldering did not help, there is a small potentiometer on both the old and new lens, after I turned it counterclockwise a little bit on the new lens, the CD- engine to do it again! Unfortunately, the problem itself persists, the player still only works when it is on its side.

I take out the component that reads the CD and keep it on its side, now it works again. The same thing happens at every angle except when I lay it flat again. So the problem is still in the reading/playing part, but I carefully exclude the lens as the cause. I'm now starting to think that the transport is not holding the CD in place properly, this is because I feel vibrations when it's flat, these vibrations disappear when I hold it on its side. This may be a hint to the cause but for me it's enough for now.

Now after almost three weeks of tinkering I have decided to leave it at that, I have plenty of other projects that I can continue with and that are now only in the way because of my small room. Time to put the Minidisc recorder back together and put it away until I feel like and time for it again.

I've learned a lot about how the Minidisc works, but that this is a typical case where it might be better to say goodbye than to spend more time and money on it.

For now I'm going to look at another copy, one that does work so that I can at least continue with the Minidisc itself.

08 August 2019 

Addition, in the end I chose to purchase another Minidisc recorder. I had several copies in mind, but the choice fell on a Yamaha MDX-9:

I've put the TEAC on the shelf for now, maybe I'll look at it again soon.

February 13, 2020

A small addition, I received a response from a visitor a few months ago.

He was able to tell me that changing the laser is the easiest of the whole repair. First of all, the type number on the new laser must be exactly the same.
(reference to another website).

First of all you need a so-called 'power meter' to (probably) measure the laser strength (I will have to delve into this).

I have been in doubt about purchasing (esd) gloves for a long time, these are also mentioned in addition to an anti-static wristband. After all, the laser is very sensitive to static discharges.

To put the icing on the cake, the laser has to be calibrated from the deck from a hidden menu...

The information sent to me comes in very handy with this already complicated repair. I would also like to thank the sender for this!

I'll keep this in mind for now,
until I find the courage to continue with the MD-H500i.

Related pages: