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MZ-M10 "stuck" on System File Writing

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Seems to be a common problem with RH10 and RH910 about now. I have already fixed my own (after a year's struggle and eventually buying the right equipment) and am fixing one as a test. If the test succeeds I may charge at least until I have recovered cost of said equipment. But let me see how I get on with the one being sent to me, first.

Analysis: the Overwrite laser power is set by using the alignment disk and there is no documented way to set it by hand. However it's possible to set it by careful measurement and backed up by calculation. So - basically the machine works fine until time to write the TOC.

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Seems to be a common problem with RH10 and RH910 about now. I have already fixed my own (after a year's struggle and eventually buying the right equipment) and am fixing one as a test. If the test succeeds I may charge at least until I have recovered cost of said equipment. But let me see how I get on with the one being sent to me, first.

Analysis: the Overwrite laser power is set by using the alignment disk and there is no documented way to set it by hand. However it's possible to set it by careful measurement and backed up by calculation. So - basically the machine works fine until time to write the TOC.

Ok, thanks, what might this cost and where are you located?

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  • 3 years later...

Three years on, sadly I am older (definitely) and wiser (perhaps). Not sure there is any really good recipe for fixing these other than:

a. taking them all apart and checking for known mechanical problems

b. running the automatic (servo) alignment using the correct test disks.

It seemed possible to fix using manual adjustments but in the end something always returned to bite me, and between myself and our resident repairman (actually he's in England) Jim Hoggarth, we decided these particular units are a horrible pain. Not least because you can get random results depending on your test disks. They may just be completely unfixable.

Some questions about your situation:

1. Do you have a laser power meter to check the basics?

2. Do you have the sidecar that you can use to run the unit on an ALKALINE (no NiMH please!) AA battery?

3. Does the writing fail on NetMD (legacy LP2 probably), Hi-MD (80 reformatted, probably Hi-SP), or Hi-MD (1GB), or on all three?

4. Do you have another unit to check the results of recording with?

There are just too many things to go wrong, which is perhaps why Sony didn't keep going on the format.

If you can spare the machine, I'd take a quick look at it, but no promises or guarantees. I have tools (laser power meter) and test disks. But even the one time someone sent me 2 units they had both been so horribly abused before I ever got them I had to send them back almost untouched. Someone had clearly attempted to fix them very clumsily and failed. I have no idea who, in that case, although I knew who I received them from.

The problem that I see is you are in Germany. Jim is out of action for the foreseeable future. We could have you take out the battery to reduce postage weight, keep the remote, and I can try.

FYI, it's much less likely that the overwrite power is really the problem. It's more about what happens when the unit tries to READ what has just been written :) But there are several angles - the head not lifting up quickly, the sled not travelling, bad power generally, and on and on.

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Thanks for your message.

I do not have a power meter. I used the 3V power supply, but I could also use a battery.
I tried all sort of discs and the failure appeared first especially at the end of a 1 GB disc that was almost full. After this, I tried recording on a blank 80 Min. disc that was used in Hi-MD PCM mode. About 1 min. was recorded correctly and then the play count stops during reading of that record. It moves suddenly by some seconds but gives no sound. I suppose, there were no bits written on the disc. Playing and editing works perfectly for all kinds of discs. Also reading the bad records on new HI-MD walkman gives the same result.

I have read in other posting that you know about undocumented Overwrite power (value 9114). Where did you get this information?

(RH 10 can only record in Hi Mode atrac3plus not atrac3.)

Yours sincerely,

wolb

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I worked out how to do less than a full alignment by looking at bunches of different service manuals including those for (full-size) decks. Those manuals are all available either here or at minidisc.org. But it really only makes sense to start at the top and do a full alignment. The problem is that if you start without ALL the tools, you get "stuck" where the unit literally will do nothing.

When the root cause is mechanical, however, electrical tweaking really isn't going to help very much. And changing the overwrite current without a power meter is downright crazy, though I admit I did it.

As I said above, the observation that you cannot write is (unless the overwrite head got bent or the raise/lower servo somehow out of synch) not as important as the ability to read immediately after writing. This is because all the checksums and stuff have to be calculated on the fly (when it says "writing system file") after you finish recording or editing.

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Thanks very much for your expert explanation! :good: :good: :good:

I think the best will be to let this equipment using only for play as long as it will live, and not to repair or adjust anything.

Before, I was planning to replace the laser unit for about 100 $, but now I am not sure it would be worth this effort.

The last recording i tried, it could not even write the TOC (was endless writing TOC) as you described in your statement.

Yours sincerely,

Wolfgang

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Question: is the display bright or dim? If bright, ignore what is below. If dim, continue.

Question: do key presses always work well? If no, then make sure you (now) try your writing tests with ALKALINE battery (not NiMH) and also with mains (not USB) power.

If you are good with your fingers, and have a reliable (calibrated!) voltmeter, I would be inclined to try the following:

1. Disassemble the machine, removing the bottom (but not the top - I think. If this direction makes no sense you will have to figure out the test points by clever means without removing the board!!! But I don't remember 100%). Get into service mode BUT DO NOT DO NV RESET. Operate from 3V DC mains adapter, to be safe.

2. Do the power adjustments on page 16, starting at paragraph 3-2 BUT NOT BEFORE! Did you have to change any voltage more than the tolerances suggested by the manual in the large table on the right hand side? If the answer is "No" you can't really expect much improvement.

3. Don't worry about page 17 and after.

4. Remove the power to exit. Don't worry about resetting anything or "resume clear" which mostly resets to factory settings.

Stephen

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Hello Stephen,

thanks for your advice!

The display is dim, I cannot read anything in daylight, in the night it is sufficiently bright to read all.

All keys work, but often another function appears when a key is pressed. e.g. when volume is pressed, the search function key below is also responding. This was already from the beginning so and has sometimes destroyed data on a disc when I was pressing the fast rewind key!!!

I tried already with a new alkaline cell, but not better recording.

Do you think, power adjustment is necessary?

Yours sincerely,

Wolfgang

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FWIW I just did a power adjustment on an NH900 and it took me about 1 hour. Didn't solve the problem I was hoping (poor voltage showing on the battery icon when I have a good battery inserted) but the machine seems to have survived the procedure. I do notice that there are no more weird things happening with keys not producing the right clicks, which should be related, since the unit senses resistance when figuring out which button was pressed.

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So, I have an NH900 which has this same problem, put a disk in and it will just start recording or setting track marks or whatever, I ruined a few disks in it and them put it on the shelf. The think is in pristine condition and I would love to put it back into service. ANy thoughts on how to assist me with that Stephen?

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Hello Stephen,

thank you for the answer. :good:

Can you explain, why the unit preferably makes the function of a key that is located in direct neighborhood of the key pressed? Could this be also a mechanical malfunction of the key sensors?

Yours sincerely,
Wolfgang

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Probably not. But maybe I don't understand your question. The key presses all depend on resistance changes. Hence, fixing the power may help. It may be more about which keys are close in resistance value (for their meaning, if you understand me) rather than close physically. It's possible that sometimes one attribute follows the other, ie the ones which are physically close also have similar (but not the same) resistance.

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Update: I just went back and did a full alignment (bricked the NVRAM with a 911 Reset! These Sony engineers have a sense of humour) and magically the power came right. Now runs perfectly. I guess I was inspired by success with E909, and persistence was in this case rewarded nicely. I too have the odd problem with keypresses but it's mostly ok now. I think maybe there was a screw missing from the board behind the jog wheel, which I must rectify at some point.

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