DVD laser deterioration?

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Maybe reduced laser output. Probably a crudy slide mechanism.

1) search for sci.electronics.repair faq. Read up on optical player repair. 2) if you've used a "cleaning disk", call it quits and chuck the unit in the trash; you've probably scratched the lens into a repair that'll cost more than the price of replacement.

I would not. In some places, here 3000 feet up in the desert, everything gets covered with a layer of powdery DRY dust. The cleaning disks often fix optical drives with no problems.

In other places, especially ones with high amounts of hydrocarbons or humidity in the air, they do just scratch things, or worse, move around the much.

The last DVD player I chucked was left on all the time, playing the menu of the disk. The rails that the laser assembly rode on were worn down at that spot. Since it cost me $30 for the player, and would cost $20 to replace it, I just gave up.

YMMV.

Geoff.

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Geoffrey S. Mendelson, Jerusalem, Israel gsm@mendelson.com  N3OWJ/4X1GM

Bedroom stuff tends not only to end up dusty (fabric dust from bed linen, clothes, dead skin, etc!) but is generally used less often than other kit. So, I'd start by opening it up, clean the lens with a q-tip dipped in alcohol, and clean and relube the sled. You may well be surprised.

Let us know how it goes.

-b

I've never used a cleaning disk.

jumping

Well... Everything else plays correctly in this player. I was really asking for anyone who had experience with deteriorating lasers.

When I have the chance, I'll pop the top and see what's going on.

Try manually cleaning the laser block optics and making sure the sled move freely. If that does no good it's time to chuck it or buy a service manual and retune the tunables. Also possible dry caps in the PSU causing some dirty DC and incorrect voltages.

Thanks.

Hi!

Well...I don't think you're ready to lose the laser diode quite yet.

I don't know what it is about DVD authoring that is so hard, or where the quality control problems come in, but I've had a few DVDs that were problematic in players otherwise known to work. Funny thing is, more often than not, many of the troublesome discs would be *fine* in a cheap Apex Digital AD-1201 player.

Go figure. Sometimes I think the movie and TV studios *know* what they're doing to make these discs have such defects.

My brother was using a 1998 era Matsushita/Panasonic DVD drive in his computer to watch movies. (Yes, the drive was cheap.) He has used the daylights out of it and only recently did it just quit reading any DVD. (Don't know about CDs.) I haven't had a chance to look at it, but it would not surprise me if its laser had simply worn out to the point where it no longer worked reliably.

William

One of the problems is that a DVD is very limited in the format, encoding, resolution, frame rate. Anything other than the few resolutions, frame rates etc, are "out of spec".

Here is a chart with the requirments for a DVD:

HOWEVER, a modern DVD player will play almost anything, as long as the internal decoder (hardware or software) will play it. Most computer programs will too, except earlier versions of Microsoft Media Player for Windows. It would play files of almost any spec, but if it was playing a DVD, it would only play ones within spec. I have not tried it in years, but I expect that limitation is long gone.

I have not seen one in years, but when DVD players first came here (around

1998-1999) the expensive Japanese brand ones were very finicy about the format of the disk, the zone, how it handled NTSC (24/10001 and 30/10001 frame rates) versus PAL (25) and so on.

The cheap Chinese ones had set up options for TV type (NTSC/PAL/auto) converting frame rate as needed, and were not very finicy. If it was an MPEG-1 or MPEG-2 encoded file, it would play it.

Maybe the disk is slightly out of spec in encoding. The only way I know how to tell is play it with mplayer on a Windows or Linux system and look at the console output. It will tell you the codec used to decode the video and audio, the frame rate, the bit rate (how much data is used for encoding), the resolution etc for both audio and video.

Note that some combinations such as MP3 audio with anything, or MP2 audio on NTSC disks are not "legal" although modern players will happily play them.

Geoff.

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Geoffrey S. Mendelson, Jerusalem, Israel gsm@mendelson.com  N3OWJ/4X1GM

I would try cleaning - and note the 7000 has TWO laser lenses in a common housing.

It's old enough to have picked up a layer of dust in there.

Also worth cleaning that particular disc - you never know...

Mark Z.

rates

Interesting. The player in question was the first commercial DVD player.

how

encoding),

I'll give it a try. Thanks for the suggestion.

One for CDs, I assume.

I looked at it closely under bright light, and I saw nothing.

I recently had a bad CD which had what appeared to be an area of bad plating. The replacement did not show this, and played correctly.

I remain amazed at the quality control of optical media. Out of the thousands of CDs I own, only two have been defective.

I've rented a couple out of maybe two hundred or so bad previously unplayed DVD movies. I usually run into maybe one bad DVDR in a 100 spindle. Same goes for CD/CDR. These have all been checked in multiple players/burners.

Back when I first got started in CD recording, late 1991, we paid $10 each for the blanks (in large quantities) and had a 10% (1 per box of 10) failure rate.

Office Depot here had a 2 for one sale and I bought 2 100 packs of blanks on sale and they have been problematic for me, with about a 5% failure rate. The usual brands I have bought, except for Verbatim, have been closer to 2% to 3%.

The Verbatim disks I sold here are their special low cost line, and I have had almost 100% failure rate with them. Compared to the ones sold in the US, these are absolute junk and a dilution of their brand. I must not be the only one who thought that because Office Depot had them on half price sale for around 6 months and no one bought them.

This is not one drive, I currently use 6 computers here with various drives in them and various operating systems. I do most of my burning on either a Mac with an external Samsung drive (upgraded from an NEC), and a Linux computer with an identical drive, but also do it on other computers with Liteon, LG and NEC drives.

Geoff.

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Geoffrey S. Mendelson, Jerusalem, Israel gsm@mendelson.com  N3OWJ/4X1GM