MDS JA30ES Strange behavior

[Balthar]

Hello,

First of all hello to all forum members.

As the title says i have a MDJA30ES and since a few months back it developed a strange problem (or not). It was not recording very well, after some time also playing with skips, then after recording a full disc it couldn't be read anywhere and give a disc error.

After send it to a service and get everything regreased and tuned the service repairman said it as recording as expected and just needed to close the lid to give it to me.

When i tried at home it gave me the same errors as before, so after a while i decided to make the test with the lid off and all went fine, recording and playing as new.

So i guess my unit is suffering some form of overheating, and after a recording session with the lid on i removed it and the deck mech as indeed very hot.

My problem now is how to solve the overheating problem, is there anything i should look for? The deck inside is like new, no dust i see no damged caps so can't figure out what's causing the overheating problem.

Thank's all

Artur

[sfbp]

Mechanism is liable to overheat when alignment or laser power are off. Jim?

[Balthar]

Mechanism is liable to overheat when alignment or laser power are off. Jim?

Problaby something like that. Can the alignment and laser power be made at home or does it require especialized tools?

Regard's

Artur

[Balthar]

I found out where to adjust the laser power but since i don't have a laser power meter i'll do it by trial. I had to remove the mech to acess the laser dial so i need to remove the allways remove the mech to adjust the laser. The unit itself should have some sort of sensor to read the laser power.

[jim.hoggarth]

Mechanism is liable to overheat when alignment or laser power are off. Jim?

Yes, very true. I am more inclined to think the regulation photo-diode in the laser emitter itself is at fault, causing the foldback laser current to be way too high and generating excessive heat. Only fix is a replacements optical pickup.

Jim

[jim.hoggarth]

I found out where to adjust the laser power but since i don't have a laser power meter i'll do it by trial. I had to remove the mech to acess the laser dial so i need to remove the allways remove the mech to adjust the laser. The unit itself should have some sort of sensor to read the laser power.

This adjustment should never be touched - it is factory set. You are in danger of just making things worse. There is a good chance the laser pickup is damaged and no amount of adjustment of the laser drive current or the servo EEPROM drive settings is going to change that. The laser unit has an internal regulator photodiode, the 'sensor' you mention, but if this is giving incorrect feedback info only replacement of the whole laser unit will help.

You say the drive unit gets very hot. Possible damage to your skin hot, or very warm, or mildly warm? After the drive has been working for some time - and especially during record sessions - there is a certain amount of heat generated. You need to quantify this level of heat somehow, so we can compare it to our experiences. But anyhow, if the drive fails with the top on it is definitely not right.

Jim

[Balthar]

This adjustment should never be touched - it is factory set. You are in danger of just making things worse. There is a good chance the laser pickup is damaged and no amount of adjustment of the laser drive current or the servo EEPROM drive settings is going to change that. The laser unit has an internal regulator photodiode, the 'sensor' you mention, but if this is giving incorrect feedback info only replacement of the whole laser unit will help.

You say the drive unit gets very hot. Possible damage to your skin hot, or very warm, or mildly warm? After the drive has been working for some time - and especially during record sessions - there is a certain amount of heat generated. You need to quantify this level of heat somehow, so we can compare it to our experiences. But anyhow, if the drive fails with the top on it is definitely not right.

Jim

Hi, thanks, I would say it's very warm, and after changing the laser power a little the disc record better then before, it no longer gives the disc error, but after trying to play it it stills skips a little, but after the deck cools a bit no longer skips, so i guess it's realy a problem with the laser power or focus, the focus is done via service menu only so it can be done. My problem with laser adjustment is i don't have a laser power meter .

[Balthar]

Hi,

Seems i've bricked the deck .

After attempting a focus bias adjustment it no longer reads and i can't make another focus bias adjustment since it can read the continuos recording disc.

Is there a way to reset the focus bias withou loading a disc, or adjusting the parameters in any other way?

[Balthar]

It's alive

I guess the way to fix a bricked after a very hard failed focus bias adjust deck is( learned the hard way)

1) in the focus adjust retrieve the 3 parameters ( in my case was A0 / A0 /A0)

2) in the eep mode i find out where those parameters where

3) change the parameters to the before bricked values

4) it's working again although the focus adjust it's not correct 100% which i can't seem to achieve.

Always take the parameters before changing them so you can go back to the previous ones ( also learned the hard way)

P.S. Can someone give the factory settings so i can try them. thanks

[Balthar]

I took it to the service repair and it probably need's a new laser.

Luck i got one new from ebay for 18£ so if it's good i guess it's a very good price.

Regard's

Artur

[Balthar]

It's working fine even without the new laser.

The bottom cover has been raised a litlle with some acrylic pieces, and with the installation of a small fan directly blowing to the laser the deck no longer gives error's at recording and playing. What a litle improvement in airflow can make. It seems the JA50Es is better in airflow since the back cover as ventilation holes the Ja30ES doesn't has.

I also managed to make a reasanoble focus bias adjust.

Now seaching for a laser power meter ( a cheap one).

Regard's

Artur

[sfbp]

The most useful thing you can do is to find out the measured current, and put it in as the IOP value to the firmware. The Service manual (and if yours is no good try one of the others, they are all basically the same) explains rather badly how this is done. They assume you have a LPM.

However there's a short cut. The heat comes because the READ (as in "read data off MD disk") power is not quite right. The first thing you need to check is that the IOP value printed on the bottom of the optical pickup is correctly entered in the firmware. Manuals say that this number is printed on a sticky piece of paper. It may be, but some kind person at the factory always writes the value in blue ink on the TOP of the head, so you don't even need to take it out.

Running it as it is now, always hot, will eventually (maybe SOON) fry (kill) the OP. It may say "0692" which means 69.2. The number should be around 70, but it has to be correct down to 1/10th of a mA (the last digit).

Once you put THAT number (using the IOPWR function in the firmware) your problem may disappear. Running hot for a long time will blow the optical pickup. Don't worry about adjusting the WRITE power (the value around 7 mW), the READ power is the one that matters. And it's this being out of whack that causes the heat, and eventually C13 and C14 errors. BTW check your AC voltage (mains) against the specs of the deck. Running a deck on slightly too high voltage can cause this sort of thing too. So if it says 220, and your voltage is 240, you may also have a problem. (I see that it may possibly be, for you, based on where you live).

LPMs are very hard to find (I have one) and cost way more than the value of most decks, around $200. You will not be able to obtain the "mark 2" version that Sony tells about with the head in the shape of a minidisc. Sorry. But the regular ones are fine. I can give you the reference if you need it.

[Balthar]

The most useful thing you can do is to find out the measured current, and put it in as the IOP value to the firmware. The Service manual (and if yours is no good try one of the others, they are all basically the same) explains rather badly how this is done. They assume you have a LPM.

However there's a short cut. The heat comes because the READ (as in "read data off MD disk") power is not quite right. The first thing you need to check is that the IOP value printed on the bottom of the optical pickup is correctly entered in the firmware. Manuals say that this number is printed on a sticky piece of paper. It may be, but some kind person at the factory always writes the value in blue ink on the TOP of the head, so you don't even need to take it out.

Running it as it is now, always hot, will eventually (maybe SOON) fry (kill) the OP. It may say "0692" which means 69.2. The number should be around 70, but it has to be correct down to 1/10th of a mA (the last digit).

Once you put THAT number (using the IOPWR function in the firmware) your problem may disappear. Running hot for a long time will blow the optical pickup. Don't worry about adjusting the WRITE power (the value around 7 mW), the READ power is the one that matters. And it's this being out of whack that causes the heat, and eventually C13 and C14 errors. BTW check your AC voltage (mains) against the specs of the deck. Running a deck on slightly too high voltage can cause this sort of thing too. So if it says 220, and your voltage is 240, you may also have a problem.

LPMs are very hard to find (I have one) and cost way more than the value of most decks, around $200. You will not be able to obtain the "mark 2" version that Sony tells about with the head in the shape of a minidisc. Sorry. But the regular ones are fine. I can give you the reference if you need it.

Thanks for the advice.

In the MDS-ja30es the laser power is adjusted by a potenciometer in the BD board:

Adjusting Method :

"

1. Set the laser power meter on the objective lens of the optical

pick-up. (When it cannot be set properly, press the 0 button

or ) button and move the optical pick-up.)

Connect the digital volt meter to TP (IOP) and TP (I+5V).

2. Rotate the AMS knob and display “LDPWR ADJUS”.

(Laser power : For adjustment)

3. Press the YES button twice and display “LD $ 4B = 3.5 m”.

4. Adjust RV102 of the BD board so that the reading of the laser

power meter becomes 3.45 ± 0.1mW.

5. Press the YES button and display “LD $ 96 = 7.0 m”.

(Laser power : MO writing)

6. Check that the laser power meter and digital voltmeter readings

satisfy the specified value.

Specification :

Laser power meter reading : 7.0 + 0.2 mW

Digital voltmeter reading : Optical pick-up displayed value ± 10%

(Optical pick-up label)

lop = 82.5 mA in this case

lop (mA) = Digital voltmeter reading (mV)/ 1 (W)

7. Press the YES button and display “LD $ 0F = 0.7 m”.

(Laser power : MO reading)

8. Check that the laser power meter at this time satisfies the

specified value.

Specification :

Laser power meter reading : 0.70 + 0.05 mW

9. Press the NO button and display “LDPWR ADJUS”, and stop

laser emission.

(The NO button is effective at all times to stop the laser"

Unfortunately i do not own a LPM so i can't make that adjustment, it seems reasanobly easy to do with a LPM.

I guess i'll just try to het one cheap in ebay or elsewhere, but since i've instaled the fan the optical unit it's running cool.

[sfbp]

If 0825 is what is actually written on your optical pickup, you should now check and see if this is correctly entered as the IOP value. If not, there's a very good chance that fixing it may stop your problem. Save the old value just in case.

Also you could try playing with the mains AC voltage to see if that makes a difference. You will need some gear to do that, though the power used by an MD deck is about 20W only, IIRC.

[Balthar]

Hi, My optical pickup reads 838.79 but i cant find the iopwr function in the service menu.

And although the deck is running it's not at 100%, it gives some read errors (sound drops). so i guess it needs a LPM to adjust the laser power correctly or even a new laser pickup, since it seems to record fine, at least the MD recorded on the Sony has no drops playing it in the Denon.

SInce i don't have one (LPM) and they are rather expensive, i'll just kep using the Denon DMD1000.

Thanks

Artur

[sfbp]

Hmmm that's a strange notation. My two guesses would be 0838 and 0879 with the extra two digits meaning something else. You need to READ IOP as set first and see if it matches. Look very carefully. Was this deck made in Europe or Japan? If Japan (most likely) then the 7 will not have a horizontal line through it. Only in Europe do we cross our 7's (and a lot of Canadians because of the French influence). In USA and UK it's still not so common.

Note that to get into the right part of the service menu is a bit tricky. There's a CHECK mode and a SERVICE mode in the later decks. Could this be the same, but not properly documented?

See the 630, for example. Right after turning on (with special buttons pressed) now you have to choose between TEST and SERVICE. One is clockwise (RIGHT), the other is anticlockwise (LEFT). Now press YES and you should be in the right place.

Maybe that's all it is.

One option is to take the drive mechanism out and send to Jim. He can repair, and replace. Then you don't have such a bad shipping problem. I have done that.

[Balthar]

One option is to take the drive mechanism out and send to Jim. He can repair, and replace. Then you don't have such a bad shipping problem. I have done that.

It's made in Japan I read 838'79

That´s a very interesting thought i didin't remember. The postage of the mechanism should be much cheaper than the fulkl deck.

Still wainting for the delivery of the new pickup unit ( 3 weeks from Germany to Portugal seems a bit to much).

Regar's

Artur

[sfbp]

Sorry you're right...the service manual doesn't mention IOPRD and IOPWR. I think you could still look in the menus, but it sounds as if this way of doing things was introduced AFTER they made your deck. Unless there was a firmware update at some point.

Bottom line - you need a LPM or a new pickup.

Be careful when tweaking read power. It frequently needs to go the opposite way to what you think (more is less, less is more!).

[Balthar]

Sorry you're right...the service manual doesn't mention IOPRD and IOPWR. I think you could still look in the menus, but it sounds as if this way of doing things was introduced AFTER they made your deck. Unless there was a firmware update at some point.

Bottom line - you need a LPM or a new pickup.

Be careful when tweaking read power. It frequently needs to go the opposite way to what you think (more is less, less is more!).

That's correct. I've discovered that tuning (mv) laser power with the multimeter reading the iop it goes up counterclockwise and down clockwise.

I've put it to read 83.3mv +/- at iop but it sill gives errors at playback.

Without the LPM it´s impossible to get it right. Also in my deck an osciloscope is nedeed to do the traverse adjustment, so even if i manage to swap the laser optical unit i will need pro tools to get it right.

regard's

[Robert Janssen]

Hello,

First of all hello to all forum members.

As the title says i have a MDJA30ES and since a few months back it developed a strange problem (or not). It was not recording very well, after some time also playing with skips, then after recording a full disc it couldn't be read anywhere and give a disc error.

After send it to a service and get everything regreased and tuned the service repairman said it as recording as expected and just needed to close the lid to give it to me.

When i tried at home it gave me the same errors as before, so after a while i decided to make the test with the lid off and all went fine, recording and playing as new.

So i guess my unit is suffering some form of overheating, and after a recording session with the lid on i removed it and the deck mech as indeed very hot.

My problem now is how to solve the overheating problem, is there anything i should look for? The deck inside is like new, no dust i see no damged caps so can't figure out what's causing the overheating problem.

Thank's all

Artur

Hi Balthar,

The problems you describe having with your MDS-JA30ES, I had those problems too.

First I could not find the reason, but I think I got it now.

I found out that my JA30ES recorded en played back without problems when I used a MD wich was never before used.

But when I recorded on a disc wich was used earlier on an other Minidisc-recorder (before the JA30ES I had the JA20ES), even when I deleted the complete disc, the problems came.

At the moment I own a MDS-JA50ES and this machine has the same problems.

So, if you still have some empty, never before used MD to record on, please try to record on your MDS-JA30ES and I think the problems will not occur.

Greetings, Robert.

[Mr. Brian]

EBay.