DVD Drive motor power

DVD spindle motors are usually brushless DC (BLDC) motors that would not work by just powering them with DC - you'd need a driver IC that creates the proper waveforms. So, my guess is that this deck has just a simple DC motor instead? Otherwise the 5VDC trick wouldn't work. How many wires are coming out of that motor?

I'm not familiar with the particular model but in those DVD drives I've seen insides of, all motors (and also any solenoids) are driven by the same IC. ROHM's BA5995FM would be one example (or others in BA68xx series). It's a 28-leads HSOP28-M package (with a thick grounding/heat sink solderable connector plate in a middle) that requires very little extra components. In other words, if the motor does not spin and the motor itself is OK, it's either the IC or the Hall-effect sensors (or whatever other sensors there may be in the speed control feedback) - either way the repair is very tricky because the faulty parts are the least serviceable.

I don't want to suggest it's necessarily your case but you may want to look around for a 28+ pin driver IC that may be connected to the motor. Then work your way from the motor (the best serviceable) down to the IC (the least serviceable)

Post more info about the motor, I may be able to help more if it's type is known.

Good luck!

------------------------------------- /_/ ((@v@)) ():::() VV-VV

Bad laser pickups are quite common. Probably a waste of time.

Sorry.

Mark Z.

motor

If the dc motor is not turning,I will advise you to remove the motor from the deck power it with external voltage source for about 4 to 5 minutes and return it.This is called dc excitation ,because, I believe the magnets inside the dc motor are loosing their magnetic properties .Hope this finds you well.If I may like to ask ,did you measure the output voltage where the dc motor is connected?

On Mon, 19 Dec 2011 19:30:09 -0700, "Chas" put finger to keyboard and composed:

Service manual:

User manual:

- Franc Zabkar

"DA" wrote in message news:2f9b6$4ef021d0$43de0cc0$ snipped-for-privacy@news.flashnewsgroups.com...

Actually, most bog-standard DVD decks found in domestic players, *do* employ a Mitsumi DC motor of exactly the same variety as found on CD decks. They frequently fail, but not totally. They are usually just reluctant to start up, and if you give them a bit of help, they will spin up the disc and operate normally until next time. Occasionally, the symptom is of slow rotation. The fact that the motor appears not to be being driven, may be a secondary symptom of the real fault. It depends on what startup sequence this particular player uses. Some will run the disc up right away, and then go looking for output from the optical block. Some will attempt to obtain focus first, and if they can't, will rotate the disc in small pulses, to see if they can find an area where they can obtain focus, just in case the first area tried was dirty, or badly damaged. But some will only try to obtain focus in one place. If that doesn't happen, perhaps because the laser is defective, the coarse spindle drive and servo will never be enabled, and power will never be applied to the motor.

The motor will be driven by (often) a small SIP IC, but sometimes by a somewhat larger IC, that looks after the sled motor as well. The switch on the small board that the motor is primarily connected to, is nothing to do with control of the motor. It is the laser 'home' switch. The board is just a convenient 'via here' point to anchor the motor's wires to. Rarely, the drive IC is actually on this little board, but mostly, it will be found down on the board that the little switch board connects to. Normally, you will find either a cable with half a dozen wires in it, going between the switch board and the main board, or sometimes, a flexiprint (not to be confused with the flexi from the laser). This cable also carries drive for the sled motor. If you look close to where that cable arrives at the main board, you will probably find the drive IC (s). You can check that there is some voltage present on the supply pins of the chip. Typically, this will be around 8 volts. If there is voltage present, but nothing is output to the motor, then you will probably not progress much further without schematics, and a degree of experience in troubleshooting the servo / drive circuitry. As a slight aside, if you deliberately move the sled some distance up the slides, then apply power, and the sled motor runs to return it 'home', as I believe you stated was the case, then the supply for the spindle motor driver is almost certainly present, as sled and spindle drives usually share a common supply. As another quick test, does it play a CD still ?

Arfa

Hey Franc. Where's the actual download link on that page ? Every time I go looking for a manual online, I keep fetching up at that site, but I never seem to be able to find the download link to the actual pdf. Everything that you can click on seems to be either a Google ad, or some ancillary program download. I'm probably being blind and dumb. Put a dopey old sod out of his misery, will you ? :-)

Arfa

On Thu, 22 Dec 2011 01:42:28 -0000, "Arfa Daily" put finger to keyboard and composed:

There is a "Get Manual" link about two thirds of the way down the page, just to the right of centre.

- Franc Zabkar

Damn ! How did I miss that ? Well, I guess because of all the big brightly coloured 'download' buttons, that are in fact just ads or ancillary programs that you don't want ...

Anyways, the manual tells all with flow diagrams for the DVD section and trouble shooting guides. It looks as though it is a two channel driver IC for spindle and sled motors, and it looks as though it requires several servo on signals to be present, before it outputs motor drive, as I suspected might be the case.

Arfa