How does one test or check DVD laser?

[Thor]

What are some simple and reliable methods of checking the laser in a DVD player?
By definition the laser would include the layer that also plays audio cd's as
well, but I am really interested in the video layer. I have DMM's and such, even
a laser power meter but that is on the bulky side.

How much trouble is it to replace the laser(assembly?) and what equipment is
needed? How about alignment, if it is needed?

I am looking at a finicky Sanyo DWM-400, about 3 years old.

I will give more info as needed.

Thanks for any help,
Thor

 

[Arfa Daily]

What are some simple and reliable methods of checking the laser in a DVD
player?
By definition the laser would include the layer that also plays audio cd's
as
well, but I am really interested in the video layer. I have DMM's and
such, even
a laser power meter but that is on the bulky side.

How much trouble is it to replace the laser(assembly?) and what equipment
is
needed? How about alignment, if it is needed?

I am looking at a finicky Sanyo DWM-400, about 3 years old.

I will give more info as needed.

Thanks for any help,
Thor

In general, there's not an awful lot you can do to 'test' an optical block,
as such. In general, if the unit plays CDs but not DVDs, or, more rarely,
the other way round, you have a better than even chance that it's the laser
(optical block) that's at fault. If your player is used a fair bit, then 3
years is not at all uncommon for the laser to be showing signs of wear.
Another good pointer is if the player starts freezing up after about 3/4 of
a full length feature film has played. This is when the player has switched
to reading layer 2 on the disc, which has to be read through the
semi-transparent layer 1, so consequently has less reflectivity of the laser
beam.

Other causes of poor playability are bad spindle motors, when they are the
brushgear'd little Mitsumi DC types, and (very) occasionally deposits on the
outer surface of the lens, particularly if it's a heavy smoking household.
Geoff in Israel who posts here, also tells me that it is more common to have
a dirty laser, if you live in a climate like his.

As far as replacing lasers goes, on most players, it's not a difficult job.
Often, the laser comes pre-mounted and aligned on a sub-deck, which also
includes the spindle and sled motors, and limit switch. Where this is the
case, it is pretty much guaranteed that it is just a 'drop-in' replacement.
Some lasers are supplied as just a 'bare bones' optical block. In most
cases, these will also just drop in, but some players, such as Panasonic for
instance, require the tilt to be mechanically adjusted. Some other players
have electronic setups to match in the replacement laser to the machine.
Most machines also have a degree of self diagnosis built in, but it's often
hard to get at unless you have a service manual, and sometimes a service
remote. In my experience, unless you have a particular liking for a player,
or if it's a HC system, and you have all its speakers and cabling 'plumbed
in' to your walls, the cost of a replacement laser is prohibitive, and you
might as well go and buy a new player, with a new 2 year warranty, at the
cheapest place you can find ...

Arfa

 

[neon]

I knew somebody will answer . Checking for what depth of penetration on the plastic angles narrow beans colors . yes you can with multimilion $ equipment

 

[Thor]

I would replace the entire assembly + drive motor + spindle motor and
control boards if you just wanted to shotgun it. A couple weeks ago I did
something very similar with a stand alone DVD burner swapping parts from a
PC burner. Here are a few pictures:

http://s273.photobucket.com/albums/jj220/meatplow1/Electronics/

This is a cheaper dvd player and the drive doesn't even have an onboard
controller. I do have an older player that could use regular PC dvd drives.

I am not coming up with much searching for anything inside this player,yeesh.


Thor

 

[Thor]

In general, there's not an awful lot you can do to 'test' an optical block,
as such. In general, if the unit plays CDs but not DVDs, or, more rarely,
the other way round, you have a better than even chance that it's the laser
(optical block) that's at fault. If your player is used a fair bit, then 3
years is not at all uncommon for the laser to be showing signs of wear.
Another good pointer is if the player starts freezing up after about 3/4 of
a full length feature film has played. This is when the player has switched
to reading layer 2 on the disc, which has to be read through the
semi-transparent layer 1, so consequently has less reflectivity of the laser
beam.

Other causes of poor playability are bad spindle motors, when they are the
brushgear'd little Mitsumi DC types, and (very) occasionally deposits on the
outer surface of the lens, particularly if it's a heavy smoking household.
Geoff in Israel who posts here, also tells me that it is more common to have
a dirty laser, if you live in a climate like his.

As far as replacing lasers goes, on most players, it's not a difficult job.
Often, the laser comes pre-mounted and aligned on a sub-deck, which also
includes the spindle and sled motors, and limit switch. Where this is the
case, it is pretty much guaranteed that it is just a 'drop-in' replacement.
Some lasers are supplied as just a 'bare bones' optical block. In most
cases, these will also just drop in, but some players, such as Panasonic for
instance, require the tilt to be mechanically adjusted. Some other players
have electronic setups to match in the replacement laser to the machine.
Most machines also have a degree of self diagnosis built in, but it's often
hard to get at unless you have a service manual, and sometimes a service
remote. In my experience, unless you have a particular liking for a player,
or if it's a HC system, and you have all its speakers and cabling 'plumbed
in' to your walls, the cost of a replacement laser is prohibitive, and you
might as well go and buy a new player, with a new 2 year warranty, at the
cheapest place you can find ...

Arfa

I used some 92% alchohol and cleaned the lens. I have taken hundres of cd
players apart and I was happy to see the focus assembly is held floating by
ribbons versus wires, a bit tougher than the wire type. After the lens cleaning
the player did play two dvd's in question but I am not sure how long this will
work.
I uselessly went googling for the optical assembly or even the entire drive but
I found nothing.

The only numbers I found are,
VR 502W SV, this is stamped in plastic and I think it is for that plastic part
only.

Two stickers on the back of the drive,
KDA898SA and W4XD8898. One of these turns up a russian web page but no actual
part.
I had a look through Dalboni and they do have an optical assembly but I have no
idea if it is for this player or not.

If you could, let me know of any other suppliers? My phone line is down for a
couple of days and when it comes back up I plan on calling Sanyo, probably to
hear them tell me to take it to a shop and they don't sell parts to individuals.

I am looking at a Pioneer DV-300-K. This seems like a newer player and the
reviews, for what they are worth, look favorable. I am looking at this player
because I don't have anything HDMI and really don't want it.


Thanks for the reply,
Thor