Friday, January 28, 2011

Blue ray repair tips

I receive a lot of questions on how to diagnose failing blue ray drives.
It appears that questions are always the same ones!

I think it is now time to provide a small guide answering these questions so that everyone gets the once and for all !

Remind of the disc launch procedure :
1 - Present the disc to be inserted.
2 - The disc is automatically swallowed.
3 - Optical bloc is placed to the center if it is there already.
4 - Laser beam is activated to detect the disc.
5 - The lens does 3 4 up and down to focalise and detect the disc.
6 - If the disc is detected, rotation is launched to read content.
7 - Rotation speed evolves while reading the disc.
8 - Disc is ejected on demand with the eject button.
9 - Data are decrypted by the main processor and sent to the main board through the cable.

Now let's see what are the parts associated to these actions :
1 - Disc detection is done by the insertion sensor.

2 - Insertion is done by insertion motor. Insertion motor is driven by the BD7956FS chip on the daughter board.

3 - Optical pickup moves are done by the sled motor. The sled motor is driven by the BD7956FS on the daughter board.

4 - Optical laser beam is generated by the laser diode of the optical pickup. To produce the beam, the optical pickup needs power supplies generated on the daughter board.

5 - Focus is done by driving focus actuators. Focus actuators are driven by the BA5888FP on the daughter board.

Laser beam is concentrated with adjustable optical convergence parts. These parts are driven by the BD7956FS on the daughter board.

6 - Disc rotation is done by the rotation motor (SPINDLE). The rotation motor is driven by the BD7956FS on the daughter board.

7 - Disc reading needs a tracking servo. Tracking actuators are driven by the BA5888FP on the daughter board.

8 - Ejection is done by the insertion / ejection motor. The ejection motor is driven by the BD7956FS on the daughter board.

9 - Data transmission to the motherboard is done by the numerical heart of the daughter board using the 60 links ribbon.


Then what are the associated failures :

1 - When the disc is not automatically inserted, insertion sensor might be dead. Its red and black cables are very thin so they break easily, connector might also be not plugged properly.

You can insert manually the disc by pushing it a bit harder, it should be then swallowed.

2 - If the disc is not swallowed several parts can be dead.
The insertion / ejection motor. It can be tested individually by putting a battery to its connections.
The BD7956FS or the daughter board's power supplies are dead.

3 - If the sled doesn't move several parts can be dead.
The sled motor. It can be tested by manually pushing the optical pickup out to the border of the disc, it should go back to the center to detect the inserted disc.
The BD7956FS or the daughter board's power supplies are dead.

4 - The main blue ray drive failure problem is the laser diode dying. Failure can be straight, it means laser diode is dead, there is no beam at all, optical pickup must be replaced. But it can also be a power supply problem.

Failure can be more vicious ! The laser diode characteristics decrease with temperature rising, but optical drives provide temperature regulation compensations. But anyway, the laser beam power decreases in time. So an optical pickup might have to be replaced even with a beam available, but too weak. And finally there is the case where the beam power is not strong enough on a PS3 ant it is on another one ! This due to parts' characteristics tolerances that are not the same from one to another PS3.

As the laser diode generates the 3 beams CD/DVD/BR, there might be a way to check which of the optical pickup or the the board is failing.
If only the blue ray reading is failing and CD and DVD are read, we can conclude that laser diode is breaking because driving parts are 90% common for the 3 beams.

If several beams are having reading troubles we can say that the board has a problem because the probability having two beams failing simultaneously is weak.

5 - A focus or convergence failure will be difficult to identify. The disc will probably not be detected, or if it is, reading will be chaotic and will stop.

6 - Rotation might not appear for two reasons :
Either the disc identification is not correct, disc will not be read.
Either there is a failure.
The can be seen when the optical pickup is at then disc center, when laser beam is on and permanent. On should see a laser point on top of the disc surface. Actually, the disc detection is correct, the laser tries to read the disc but the disc doesn't spin.
Either the rotation motor is dead or the board has a problem.

7 - A tracking failure is hard to identify. I didn't see any ! Check the BA5888FP and the daughter board power supplies.

8 - If the disc is not ejected several parts can be dead.
The insertion / ejection motor. It can be tested individually by putting a battery to its connections.
The BD7956FS or the daughter board's power supplies are dead.

9 - A problem with the drive is that sometimes it is not seen by the PS3.
Main reasons are a broken connector on the main board (replace it), cable is broken or daughter board is not the original. For now I don't have a methode to make the identify the difference. Finally, if the daughter board is dead (power supplies or other) the drive won't be seen too.


Global checks :

In a general way, a method to identify if a part is failing it is to try another one, or try it in another working drive.

In the case where the BD7956FS or the board's power supplies are dead. It is not easy to identify, but a good lead would be to say that if the drive is seen by the PS3 then it is rather the BD7956FS, whereas it is not the case, it's rather the board's power supplies.

Obviously don't forget to check cables, the state of their pins and that they are properly inserted in the connectors.

Famous failures :

* Tac tac tac tac after reassembly.

(For better understanding take a look to article "Blue Ray drive explained : mechanical mechanisms" )

The tac tac tac problem is the following. When the left lateral part is in the "bottom" position when it shouldn't, upon the next start there will be another insertion process, so the pinions running on the rack at the bottom of the left lateral part will try to place it to the bottom position whereas it is already there! The tac tac tac corresponds to the pinion's teeth jumping on the rack's teeth because it can't move further.

The solution is to get the drive in its initial position. This means sled down, left lateral in "up" position, right lateral in "bottom" position. It initializes in a way the mechanical positions.

Most of the time when the left lateral part doesn't get back to its up initial position is due to the V part at the back of the drive that has its lugs out of its location in the left lateral part.

To solve the problem :

- Force the left lateral part to be in its "up" position. For this you will really have to go strongly on it ! It is a little bit baffling, but when I do it I get a big noise, as the teeth of the parts will pass on each other.
- Once the left lateral is up, check that the lugs of the V part are well placed. For that, check that when moving up and down the right lateral part, well the left lateral part follows the moves. Be careful that the initial position of the left lateral part is that teeth are not engaged i s the rack.
- Reassembly the drive, check that the upper cover gets in place easily.
- Restart the PS3, the drive should be mechanically re initialzed and should work properly.

Tuesday, January 25, 2011

Diagnostique de base du lecteur blue ray

(English just above)

On me pose beaucoup de questions pour diagnostiquer les lecteurs en panne.
Je m'aperçois que ce sont toujours les mêmes questions qui reviennent !

Je pense qu'il est temps de fournir un mini guide de réponse à ces questions afin que tout le monde ai les réponses une bonne fois pour toutes !

Rappel de la séquence lancement d'un disque :

1 - Présenter le disque à l'entrée du lecteur.
2 - Le disque est inséré automatiquement.
3 - Le bloc optique est ramené au centre si il n'y est pas déjà.
4 - Le faisceau laser est activé pour détecter le disque.
5 - La lentille fais 3 4 montées / descentes de focalisation pour détecter le disque.
6 - Si le disque est détecté la rotation est lancée pour lire le contenu du disque
7 - La vitesse de rotation évolue pour lire le contenu du disque
8 - Le disque est éjecté lors de la demande sur le bouton eject.
9 - Les données sont décryptées par le processeur de la carte fille et transmises à la console via la nappe.

Maintenant quels sont les organes du lecteur associés à ces actions :

1 - La détection de la présence du disque est réalisée par le capteur d'insertion.

2 - L'insertion est réalisée par le moteur d'insertion. Le moteur d'insertion est piloté par le BD7956FS de la carte fille.

3 - Le déplacement du bloc optique est réalisé par le moteur de chariot (SLED). Le moteur SLED est piloté par le BD7956FS de la carte fille.

4 - Le faisceau laser est produit par la diode laser du bloc optique. Pour produire le faisceau laser le optique nécessite des alimentations produites par la carte fille.

5 - La focalisation est réalisée par le pilotage des bobines de focalisation. Les bobines de focalisation sont pilotées par le BA5888FP de la carte fille.

Le faisceau laser est concentré par des éléments optiques de convergence. Ces éléments sont pilotés par le BD7956FS de la carte fille.

6 - La rotation est réalisée par le moteur de rotation (SPINDLE). Le moteur de rotation est piloté par le BD7956FS de la carte fille.

7 - La lecture nécessite un asservissement de position appelé tracking. Les bobines de tracking sont pilotées par le BA5888FP de la carte fille.

8 - L'éjection est réalisée par le moteur d'insertion/éjection. Le moteur d'insertion est piloté par le BD7956FS de la carte fille.

9 - La transmission des données est réalisée par la partie numérique de la carte fille et via la nappe 60 points entre la console et le lecteur.

Enfin quelles sont les pannes associées :

1 - Lorsque le disque n'est pas inséré automatiquement le capteur d'insertion peut être défaillant. Sa nappe rouge/noir étant très fragile, les fils peuvent être cassés ou le connecteur mal enfiché.

On peut insérer manuellement le disque en poussant le disque, il finit par être avalé.

2 - Si le disque n'est pas avalé plusieurs choses peuvent êtres HS.
Le moteur d'insertion / éjection. On peut le tester en mettant une pile à ses bornes.
Le BD7956FS ou les alimentations générées sur la carte fille sont HS.

3 - Si le chariot ne se déplace pas plusieurs choses peuvent êtres HS.
Le moteur SLED. On peut le tester en poussant manuellement le chariot vers l'extérieur, il doit revenir au centre pour détecter le disque.
Le BD7956FS ou les alimentations générées sur la carte fille sont HS.

4 - Le principal défaut de panne du lecteur blue ray est la défaillance de la diode laser. La panne peut être franche, c'est à dire que la diode est morte et il n'y a pas du tout de faisceau laser, il faut changer le bloc optique. Mais cela peut aussi être une alimentation défaillante sur la carte fille.

La panne peut être plus subtile. En effet les performances de la diode laser baissent en fonction de la température, mais les lecteurs optiques intègrent une régulation de compensation. Cela n'empêche que la puissance du faisceau baisse avec l'usure. Donc un bloc optique peut être à changer même avec un faisceau présent, mais trop faible. Et puis il y a le cas limite où le faisceau est insuffisant sur une console mais suffisant sur une autre ! Ceci est dû aux différences de caractéristiques des composants d'une console à l'autre.

Etant donné que la diode laser génère les 3 faisceaux CD/DVD/BR, il y a peut être un moyen de vérifier si c'est le bloc optique qui est défaillant ou la carte fille.
Si seul le BR pose problème et que les autres supports sont lus, on peux en conclure que c'est la diode laser qui lâche car l'électronique de commande est la même pour les 3 faisceaux.
Si plusieurs supports posent problèmes on peut pencher pour un problème carte fille car la probabilité que deux faisceaux lasers soient défaillants simultanément est faible.

5 - Une panne de focalisation et de convergence sera difficile à diagnostiquer. Il y a de fortes chances que le disque ne soit pas détecté, ou si il l'est la lecture sera chaotique et finira par s'arrêter.

6 - La rotation peut ne pas avoir lieu pour deux raisons.
Soit l'identification du disque n'a pas réussie, le disque ne sera pas lu.
Soit il y une panne.
Cela peut être vue lorsque le chariot est au centre, que le laser est présent et permanent. On doit donc voir un point lumineux à la surface du disque. En effet, la détection du disque est ok, le laser essaie de lire le disque sauf que le moteur ne tourne pas.
Soit le moteur est HS, soit la carte fille a un problème.

7 - Une panne sur le tracking est difficile à diagnostiquer. Mais je n'en ai jamais vue ! Vérifier le BA5888FP et les alimentations de la carte fille.

8 - Si le disque n'est pas éjecté plusieurs choses peuvent êtres HS.
Le moteur d'insertion / éjection. On peut le tester en mettant une pile à ses bornes.
Le BD7956FS ou les alimentations générées sur la carte fille sont HS.

9 - Un des problèmes courant avec le lecteur blue ray est qu'il n'est pas vu par la console.
La principale raison est que le connecteur de la nappe est cassé sur la carte mère, dans ce cas il faut changer le connecteur. Ou alors la nappe elle même est défectueuse.
Une autre raison est que la carte fille n'est pas celle de la console. Je n'ai pas pour l'instant de méthode pour faire la différence.
Enfin, si la carte fille est HS (Alimentation ou autres), la carte ne sera pas vue.

Vérifications générales :

D'une manière générale pour identifier si un élément est en panne, le mieux est d'en essayer un autre ou de l'essayer sur un autre lecteur.

Le BD7956FS ou les alimentations générées sur la carte fille sont HS.
Ce n'est pas facile à déterminer, mais un bonne piste est de dire que si la carte fille est vue par la console alors c'est plutôt le BD7956FS alors que si ce n'est pas le cas, ce sont plutôt les alimentations car elles alimentent aussi la partie numérique.

Évidemment on n'oubliera pas de vérifier toutes les nappes, l'état de leurs contacts, et qu'elle sont correctement enfichées dans les connecteurs.

Pannes classiques :

Le tac tac tac tac après remontage.

(Pour mieux comprendre regardez l'article "Blue Ray drive explained : mechanical mechanisms" )

Le problème du tac tac tac est le suivant. Lorsque la pièce latérale gauche est en position "en bas" alors qu'elle ne devrait pas, lors du prochain démarrage il va y avoir insertion et donc les pignons en prise sur la crémaillère en bas de la pièce latérale gauche vont vouloir la mettre en position en bas alors qu'elle y est déjà ! Le tac tac tac correspond aux dents du pignons qui sautent sur les dents de la crémaillère puisque la pièce latérale ne peu pas aller plus loin.

La solution est de remettre le lecteur en position initiale. C'est à dire chariot en bas, latérale droite "en bas" et latérale gauche "en haut". Cela réinitialise en quelque sorte les positions mécaniques.

Maintenant le fait que la pièce latérale gauche ne soit pas remontée est du au fait que le V au dos du lecteur n'est plus en place, l'un de ses ergots est sorti de sa pièce latérale.

La solution est la suivante :

- Forcer la pièce latérale gauche à être en haut. Pour cela il va falloir forcer vraiment pour la faire remonter, c'est un peu déroutant, mais moi quand je le fais je ne fais pas semblant ! Il devrait y avoir un gros bruit, ce sont les dents de la crémaillère qui vont frotter.
- Une fois la latérale gauche en haut, il faut vérifier que les ergots du V sont bien logés. Pour cela, vérifier que lorsque vous faites bouger la latérale droite et bien la latérale gauche bouge de la même manière. Attention la position de repos de la latérale gauche est que aucune dent du pignon ne soit engagée dans la crémaillère.
- Refermez le capot, vérifiez qu'il se met en place facilement, que rien ne le soulève légèrement d'un côté ou de l'autre. Si c'est le cas c'est qu'il y a autre chose qui n'est pas en place.
- Redémarrez la console, normalement le lecteur doit être réinitialisé mécaniquement et doit fonctionner.





Enfin, je vous rappelle que je propose un service de réparation pour toutes ces pannes (hors remplacement bloc optique) que vous pouvez trouvez dans l'article "Service de diagnostique / réparation".

Sunday, January 16, 2011

BMD-001 board : high level synopsis

OK, this first part will let us have a look at the board at a high level, in order to have an overview of the board.

This will let us list the major components on it, which will give us an idea of the main functions.

So next is a high level synopsis of the BMD-001 board:



Let’s give some details.

1) Power Supplies
The drive receives its main supplies from the motherboard, with a +12V and a +5V. On board, several sub power supplies are generated. Some are dedicated to digital section and some are dedicated to analog section. Some of theses supplies are critical and have to be clean. A lot of optical drive failures a due to power supplies failure.

2) Oscillator
This is the board’s main reference clock. The main processor generates all the board’s clock from this reference clock.

3) Flash memory
This memory contain the main processor’s firmware, the security keys (the one that links the board to the motherboard), and probably some board’s configuration parameters.

4) EEPROM memory
Generally this type of memory is used to store the most used configuration parameters of systems.

5) The DRAM memory
This is the working memory for the main processor; it runs firmware and stores its variables. The firmware is probably decompressed here from the flash memory by the boot loader, or it can be run from the flash, I don’t know. But for speed constraints it should be ran from DRAM memory.

6) Motherboard connector
This is the communication channel with the motherboard. It is based on an ATA link protocol with other secondary signals.

7) The audio processor.
This one seems to have SACD dedicated interfaces. As it disappears in the BMD-002 board and as the PS3 didn’t support SACD any more, either it does only SACD processing, either it does all sound processing. I don’t know.

8) Optical pickup processor
This component handles extraction data from the optical pickup. It is quite complicated as optical drive implementation is a complex system!

9) BA5888FP
This component is a power driver dedicated for CD and DVD. Motor driving functions are not used, only actuators for focus and tracking are used.

10) BD7956FS
This component is a power driver dedicated for CD, DVD and blue ray. Motor driving functions are used for insertion/ejection, sled and spindle motors. Actuators functions for collimating lens control.

11) Insertion sensor connector
This famous black and red little connector powers the photo led emitter. This part or the tiny cable are quite often failure parts, which results that the disc is not automatically swallowed, but if you push it manually a little bit further, it will be inserted anyway by the insertion mechanism.

12) Insertion motor connector
This connector interfaces the BL1-001 board which carries the loading motor and some mechanical switches that provide information on the disc position and disc format detection (12 or 8 cm).

13) Sled motor connector
This connector directly drives the sled motor, which defines the optical pickup moves.

14) Spindle motor connector
This connector interfaces the MITEC spindle motor board, which carries the motor and its hall sensors.

15) Main processor
This is the heart of the board. It is a complex microcontroller because it handles all functions and its package has a lot of pins. The challenge is to classify by functions his pins, which shall help understand the system.


Enjoy !

Sunday, January 9, 2011

Blue Ray drive explained : mechanical mechanisms

Hi,

Here we go; I will try to give you information to understand how the blue ray drive works!

First we will see the mechanical mechanisms to handle the disc in order to read it.
Then we will analyze the controller board which does the entire job!

1) The mechanical parts

Well the first thing to say is that an optical drive is quite a complex stuff and it integrates very complex mechanisms and technologies. And SONY did quite complicated stuffs for little functions, for example the insertion trap, but we’ll see that later!

Lets resume what is the function desired.

All this drive has to do is to grab the disc, drop it on the spindle motor, read the data by rotating the disc and eject the disc back out. And that’s it!



On this picture we can see:
- The disc slot is where you put the disc to insert it, and it is where you get it back once ejected.
- When you place the disc inside the disc slot for some millimeters, the insertion sensor detects the intrusion which launches the insertion process.
- The insertion process will place the disc onto the rotation motor. As the rotation speed can get quite high, the disc has to be mechanically fixed to the rotation motor. The white magnetic spindle does this thanks to it magnet which will stick the disc on the rotation motor.

The next picture shows the bottom side of the drive.



There you find the controller board which is called “daughter board” as it is attached to the main board of the PS3.

And the other very important stuff is the mechanical transmission part, which looks like a big V thing, which goal is to link mechanically two big plastic parts inside the drive! When one is going up the other is going down, and the other way.

Here are these parts on an open view of the drive.



As I said the disc is grabbed at the entrance of the drive. This is done by the disc insertion grabbers that take the disc in, as they are in rotation. As the disc gets in, these wheels are pushed to the sides of the drive, always keeping a pressure on the disc.

As the disc reaches its final position over the rotation motor, several things append.

The rotation motor (which is on the tray) is below the disc, as the disc gets in the whole tray goes high, reaches the disc and pushes the disc on the magnetic spindle to get it mechanically maintained. In the same time the disc insertion grabbers are arriving at the end of their translation and they free the disc to let him get catched by the rotation motor spindle.

Now the disk is free to rotate thanks to the rotation motor.

This last process it done by a really complex mechanical mechanism which involves many parts.

These last actions also drop the insertion trap with the insertion trap control; a mechanism locks it closed, in order to not insert another disc. This is done by the insertion trap lockers.

Now let's see the insertion parts.



The major parts are the two lateral elements.

But before, let's talk about the complex mechanism that SONY made, just to shut and lock the insertion trap!

When the disk is inserted, the right lateral part moves up, which frees the insertion trap control, which has a spring to place it when the right lateral part leaves. While the insertion process is running, and that the insertion motor is turning, the rotation motor is also used to rotate the white gears at the bottom which makes the bottom left polley turn, which uses the driving belt, activating the bottom right polley to turn, which pulls the big bottom white part to the right, raising the two insertion trap lockers. During the ejection, these elements are removed back to their original position using the spring.

Isn’t that complex just to lock the trap??!!

Let’s go back to the insertion.

As you can see on the picture, the insertion motor drives some more gears on the bottom left. And the main point, is that it drives the trammel on the left lateral part. This pulls this part down, which pulls the right lateral part up (thanks to the big V part). As these parts move, it brings up the tray.

The parts that we can see on the left of the picture are placed above the disc and drive. These parts have lugs that go into plastic guides that we can see on the two lateral parts. So when the two lateral parts move, the lugs are forced to follow a path that make the above part move in a particular way. These parts are used in the handling of the disc during the insertion.

So now for the ejection it is the other way.

The ejection motor pushes with the gears the left lateral part up, which pushes the right lateral part down. The tray is going down which frees the disc that is catched by the grabbers that eject it out of the drive. As the right lateral part is going down it pushes back the trap insertion control part which opens the trap to let the disc go out, which has previously been unlocked with the polleys thing.




Well, I surely forgot some details but it gives you an idea on how this is quite complex and that each part has a dedicated function. So if you mess up with one when you open the drive, it surely will have mechanical problems when you use it again.

If you have to get in the drive, use tutorials, get a precise look at what you touch (how, when, where) and put it back the other way in the same manner!




Well next time we’ll focus on the daughter board!

Coming soon….

(I'm not happy with my english on this one, feel free to point out corrections !)