MZ1 minidisc unit with rubber keys falling a part...

[DigitalSound]

Hello to ALL.

Last week i went into a second hand shop (all kinds of items!) and i found one Sony MZ1 unit (first minidisc unit!) available to buy. The unit came with ALL original items and original box, like new, almost like it was back in 92/93 (it includes cables, battery, user manual and original 60 minutes recordable discs plus the two pre-recorded minidisc samplers!!!)

The only problem i found is that the rubber keys are falling a part. The numbers are disappearing and the rubber is "melting" away slowly by contact with fingers and normal use.

How can i stop this process or at least use a specific substance (chemical!?) to avoid this to go any further?

I appreciate any ideas.

Thank you in advance.

PS:

About this unit... It's fully functional, and the sound... Well, now that i tested it i would like to go back to 92/93 and "bang the head" of some audio critics...

I NEVER had the chance to test this unit in the past, but i can assure everyone that the sound is good, NOT like most people (that adopted other formats at the time) said!

I was really surprised because i was expecting a really "bad sound" both on recording and playback, not true at all.

Best regards,

DigitalSound

[Odyssey]

Hello to ALL.

Last week i went into a second hand shop (all kinds of items!) and i found one Sony MZ1 unit (first minidisc unit!) available to buy. The unit came with ALL original items and original box, like new, almost like it was back in 92/93 (it includes cables, battery, user manual and original 60 minutes recordable discs plus the two pre-recorded minidisc samplers!!!)

The only problem i found is that the rubber keys are falling a part. The numbers are disappearing and the rubber is "melting" away slowly by contact with fingers and normal use.

How can i stop this process or at least use a specific substance (chemical!?) to avoid this to go any further?

I appreciate any ideas.

Thank you in advance.

PS:

About this unit... It's fully functional, and the sound... Well, now that i tested it i would like to go back to 92/93 and "bang the head" of some audio critics...

I NEVER had the chance to test this unit in the past, but i can assure everyone that the sound is good, NOT like most people (that adopted other formats at the time) said!

I was really surprised because i was expecting a really "bad sound" both on recording and playback, not true at all.

Best regards,

DigitalSound

It sounds like you found something that someone took a great deal of care of. I started with the MZR50, which I don't believe was too far down the line from when yours was produced. You have to remember, other than leaving functions out on various MD recorders for marketing purposes, the ability to reproduce sound would become better as they moved up to the next model production. Thus, the MZR1 was a great sounding unit, but it is blown away by the RH1 or M200, which in my opinion is the best MD recorder SONY ever put together.

I had to look at a picture of the MZ1 to see what type of buttons SONY used, they do appear to be the rubber type. I read somewhere that SONY used parts from a Dictating Machine to keep cost down, the display of the MRZ50 is from a Dictating Machine, so I have read, also. I Think because it was a new product, SONY tried to keep the cost down as long as they could.

So its great to hear that you have all the functions working, the electronics inside these units keeps working a long time unless you drop it a few times. These machines don't like that much

.

The bad news is the button coverings... Rubber generally has a limited life, it takes a beating with UV and just atmosphere, slowly drying out. It would seem those buttons have lasted a long long time for that machine and It seems SONY realized this because I can't think of another MD unit that uses that type of button covering.

In time, rubber will become brittle and flake away, crack, all good things rubber can do when it degrades.

Automobile vinyl covered dash boards use something that is applyed periodically to try to protect the vinyl from cracks and drying out. In the case of your buttons, it is most likely too late as the damage has already occurred and/or over this amount of time, the rubber compound they used just naturally degenerated. The more you use the buttons, the more they are going to flake apart.

Sensibly speaking I don't think there is anything that you can do, without taking away from the looks of the equipment, to stop the buttons from falling apart.

Rest assured, when the button finally falls completely apart, it will stop working because on the bottom of the button there is a resistant pad and when you press the buttonn it makes electrical connection with two copper contacts which will trigger the function required. When that resistant pad is gone, it will stop working. The buttons are difficult to replace even if you could find replacement, which I doubt.

UNREALISTICALLY speaking, I have to ask how badly do you want to keep this unit working? I am not a pro but I have done some saves of older things at one point or another, and this is a first at this type of problem.

But give this consideration

You say the buttons are working perfectly, only the rubber is cracking and coming apart..... I assume most of the buttons remains.

I just looked at the MR1 pic again, the buttons with the numbers seem to be in a slight depression, for finger contact with the buttons.

I am thinking maybe clear silicone sealant. Silicon remains flexy and should allow the press of the buttons to make contact as normal, may be a bit stiffer to press but would work.

There will be a couple of steps.

Take some plastic food wrap, lay it flat on a table or flat surface, apply a bead of clear silicone ON THE PLASTIC wrap long enough to cover the area that the buttons take, making it larger/longer is ok, this stuff will cut with sissors.

Lay another piece of plastic over the silicone and press with something flat. You want to be about 1/16 inch thick so you can use pennys to make that space holding the flat object up. You are using the plastic to keep a flat shiney look to the silicone. Try to keep any wrinkles in the plastic stretched out. Once you have this prepared, let it cure, it will take a few days.

Now for a test version

after a few days, remove the flat object, slowly and carefully remove the plastic coverings, at least one side. You will find the edges are cured but the inside is still soft and curing. Once the inside is cured more, maybe another day you are ready.

Cut the silicone to cover all the numbered buttons and the round button to the right. Leave some overlap as this is a test version.

temporarily tape some plastic wrap to cover the buttons. Make it large as this is not a finished piece, you just want plastic between the MR1 and the silicone. Cut it large enough that any silicone you apply will not touch the MR1 body. Now apply enough silicone ONTO THE PLASTIC WRAP over the buttons, to fill the space and form the silicone over the buttons when you press the flat piece of silicone you made previously. You may need to put something that weighs light over it to hold it down. Again, it will need a couple of days to cure. This is because the plastic does not breathe and the silicone needs air to cure.

After a couple days, when you remove the plastic wrap with the silicone on it, from the MR1 you should have a perfectly formed silicone cover of the button area. Remove the plastic wrap and trim the silicone to shape. If it is still sticky you may want to allow it to cure another day.

TEST

without applying silicone, lay the button mold over the buttons and operate the MR1. You want all functions to operate as before. My thought is the silicone is flexy enough to allow the buttons to perform their function.

PERMANENT

If you feel absolutely sure that this is working as you need it you need to make a decision to glue temp or permanent.

I am not sure how long the rubber will stay together, only you can determine that.

A TEMP glue down might be to just use a touch of silicone to the edges of the silicone form. It will somewhat protect the buttons and may allow easier disassembly if it is ever needed in the future.

PERMANENT glue down is at your own risk. You would glue to fill in all the void and the button surface.

Tape around the area just big enough for the silicone form to fit inside the tape, apply the silicone, press down, and carefully remove the tape leaving a clean button surface, which will now be more or less, flat.

POSITIVE: the silicone will hold the buttons together, even the cracked pieces. The silicone is flexy so there should be no lost functions.

NEGATIVE: If the buttons ever have to be taken out, the silicone would have to be cut off around each button to allow this.

Another way, which I have no idea how you could acheive this, would be to use clear silicone and form around each button individually. How you can do this and make it look good, I don't have a clue.

Well this is my thought, and I have done some work with clear silicone and this process before so I know it works where I used it before. But I will caution that I did not use it on buttons like these. If you do hazard to try this, it would be at your own peril. No Guarantees here. You are trying to save something that probably should be in a museum and altering it will cause the value to drop.

I think if you do everything up to the temp trial, you would be ok, you can throw out the silicone if it does not work well. But let me assure you, PERMANENT is just that. You can remove cured silicone but it is a mess and I can't guess what the surface of the case would look like if you tried.

JUST A THOUGHT FOR YOU......

Keep Those MDs Spinning! WHY ELSE ARE YOU HERE?