Any instructions for opening a 1633s and cleaning the lens?

Drive = Lite-on 1633s@1653s using CS0T firmware

For the last year, I've been getting excellent scans with TY's and Verbatim +R's, so I thought there was no need to get a new drive. However, since yesterday I've noticed that the 8x burns are taking almost 2x as long, and more importantly, the disks have a blank, 1/8" wide curved streak from the inside to the edge of the disk. Amazingly the disks play but do very poorly on disk scans.

I've tried resetting the EEprom and reloading the burning software but no luck.

Knowing that CD cleaning disks rarely work, and having some experience cleaning cassette tape heads in the past, I decided to open the drive and clean the lens with a Q-tip and alcohol, since it's two years old and off warranty.

Thinking that I would see the lens immediately, I unscrewed the back, and after pushing some notches I took off the back cover. However, I don't see the glass lens. What I see is the green Sony motherboard. In the middle of two separate green boards patched together by a 2" cable is a metal plate held down by three screws. This appears to be the laser lens assembly. In the middle of the metal plate is a raised nub which is also held down by three screws. Is this covering the lens? I've tried every little screwdriver I have, even one used for eyeglasses, and can't unscrew these little Philips screws.

I've also read that someone here has applied WD40 to the drive tray rails so that the tray opens more smoothly. I would like to do that as well but I can't even get the front plate off! I see two notches on the side, but only the bottom edge of the plate comes off, along with the smaller portion of the green Sony mobo.

Is there any secret to opening this drive properly? Are there any guides on this site or around the net?

I've concluded that I have to buy a new drive this week, but it would be nice to save this one and use it as a 2nd drive.

Good luck

Yeah, let us know how it goes. I wouldn't use a q-tip because I think they shed a lot of lint.

I once successfully cleaned the lens of an old audio CD player. That one was easy, but the case was as big as a breadbox. I used a microfiber cloth. The kind used to clean camera lenses and the contacts on memory sticks, etc.

Interesting that there are Sony boards in there.

Here's a picture of what the inside looks like. Can someone explain how I can get to the laser lens from here?


http://www.cdrinfo.com/Sections/Arti...nner_Large.jpg

Only use compressed air to clean out the drive. Drives PUH is a very sensetive part and shouldn't be messed with.

BTW, SONY text on pcb has been there since SOWH-812S drives, but that is a long storry way of topic.
Edit. WiltonParmenter, I can't see any Sony text on linked pic. /joke.

Yes, but since nothing else is working, and I plan to replace the drive anyway, I'd like to try to clean the laser lens. I've read several posts over the years on this board from members who've done it. Can the lens be cleaned on this drive?
Someone must have the answer and also know how to remove the front bezel!

In the meantime, now that I need a good deal, I don't see one on Lite-Ons and Benq's. I'm looking for a model that's not the latest or the fastest, since I think the best scans are at 4x or 8x. I don't need Lightscribe. I also prefer retail to OEM because with OEM you never know if you're getting a used unit.

I've only cleaned an older model CD_ROM lens once, but are you sure that is the side of the board that faces the burning side of the disc? It looks to me as if you would find the lens on the other side.

If you're sure that is the correct side my geuss would be that the lens is the thing peeking out of the largest hole.

Here are some instructions with pictures. None of them is the same model, but maybe they'll help you figure it out.

http://www.sterpin.net/uk/cleaningcombotiuk.htm

http://www.llamma.com/xbox/Repairs/c..._dvd_drive.htm

http://www.sterpin.net/uk/cleaningburneruk.htm

I think it's the other side that faces the disk. It's just that you have to unscrew the bottom of the unit to start it all off. My problem is that once I get to that point, I can't seem to unhinge the top cover or remove the front bezel as indicated in the last link you provided.

Your photo shows the wrong side. The only screws you need to remove are the four external phillips head screws that hold the metal case onto the drive. You must remove the disc tray door cover and the front panel/bezel first.

Finesse is better than force when working with the plastic tabs during disassembly.

Step 1 Remove the disc tray door and front panel.

Retail LiteOn drives ship with two bezels (black and white) and include instructions for swapping them. You may be able to get the Front Panel Replacement Guide from LiteOn. The graphics are helpful.

Insert a paper clip into the eject hole and pull the disc tray out about 1 inch. Turn the drive over. With the bottom side up, gently pull out on the door cover at end of disc tray. Once the two tabs clear the door should slide toward the top of the drive.

With the door removed, push the disc tray back in. Press in on the three plastic tabs to unlatch the front panel/bezel and gently remove.

Step 2 Remove the metal cover.

Four small phillips head screws hold the metal cover on. Remove the screws and pull off the cover.

Step 3 Turn drive right side up and use a paper clip to eject the disc tray.

With the disc tray extended you should now see the laser lens assembly. No further disassembly is required.

Step 4 Carefully clean the lens.

Use a soft bristle artist's brush that is clean and dry to brush dust off the lens. If you use a can of compressed air to blow out the dust be sure to hold it upright. Use lens cleaning solution and lens tissue for camera lenses. Apply solution to lens tissue. Gently clean the laser lens.

Assembly is reverse of disassembly. Push the disc tray back in. Replace the metal cover but leave the screws slightly loose. Install the front panel/bezel and tighten the screws. Install the door cover. Check the jumpers and install the drive. Do a test burn.

That's all folks.

BTW I wouldn't use WD-40 on the drive rails. There is usually enough residual grease on them that you can use a qtip or your finger to push it where it needs to go. WD-40 is a lousy lubricant. A better alternative is some DRY chain lube with a high teflon count available from most bicycle shops. Some bike shops may carry DuPont teflon grease which comes in a plastic syringe. Best not to over-lubricate. A little goes a long way.

Wow! Prices have really jumped on DVD burners, especially retail units. When my 1633s started acting up I looked at the LiteOn SHM-165H6s. Initially the prices were around $35 US for the retail version, then in a couple of days went up to $40. After that they weren't available. I found a listing on Amazon and ordered one for $40. It shipped from TigerDirect on Nov 15 2006. As of Jan 4 2007, the same drive lists for $64 on Amazon.

Jan 4 2007 prices-

TigerDirect Retail DVD burners:

LiteOn LH-18A1P-186 $45 in stock.
Sony DRU810A $45 in stock.

NewEgg Retail DVD burners:

LiteOn LH-18A1P-186 $34 in stock.
Sony DRU120C $45 in stock.

My old 1633s with BSOY still burns Yuden000-T02 at 8x better than the new 165H6s with HSOE. Neither burned Memorex 2.4x DVD+R DL's well. The 165H6s does a very good burn with Verbatim 2.4-4x DVD+R DL's which are MKM001 at 4x.

Good info Hoku. I have a 1693 and a 165H6. My 1693 reads TY T02 better, and it reads and burns MKM A02 much better. Sad but true.

I've decided the only way to properly burn anything with the Memorex label is in a bonfire.

Thanks so much for responding. I've gotten so far as to remove the front bezel and tray door. I had to unscrew the bottom plate before I could remove the bezel, though.

When you state that I should remove the metal cover in step #2, do you mean the bottom cover plate , or the metal covering for the entire unit?
I can only remove the bottom plate.

I've turned the drive right side up and extended the tray. Where exactly is the disk lens? I thought that in order to see the lens, mirror and glass, the top metal cover would have to be removed, too. I cant seem to remove the top cover, though.

I do see that there's one plastic tab on each side of the unit, about halfway in. When I push these in, the top cover comes halfway off, but only raises 1/2" or so.

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Last edited by WiltonParmenter; 05-01-2007 at 08:52.

Sorry, I was going from memory which was missing a few details.

Be careful handling the unit with the covers off. The capacitors on the circuit board may still have a residual charge. Make sure you are not statically charged yourself. I always unplug the computer, then press the power button and hold it for about 20 seconds before opening the case. Hopefully this will discharge the capacitors.

Once you get the back cover off, stand the unit up on its front with the open back toward you. There are two metal tabs at the very back that need to be pulled apart with some force. The unit should pop out a little from the metal case. Push in the white plastic side tabs with a flat blade screwdriver. The entire unit should now slide out of the metal case. If it gets a little cocked it will bind. The attached photos illustrate the tabs and laser assembly.

Hoku, I just want to thank you for all your time and effort to explain the construction of this drive. Not only did you post pictures, but you used Photoshop to circle the important parts!

Tonight, I was able to open the drive and clean the lens (with a Q-tip and alcohol). What surprised me is the placement of the lens. I thought there would be a one square inch glass covering to protect it, but that's not the case.

The inside is not exactly hermetically sealed either. I found some hairs near the lens, attached to the sticky part of the round object that turns, which I assume is the disk motor. That's the circular part right next to the lens. The sticky substance is probably there to attract the dust and hairs away from the lens. There was also a collection of dust inside the case.

Considering that the lens is not shielded from the rest of the unit nor the DVD, it is somewhat amazing that the scans we achieve are sometimes excellent. It would be interesting to see how the expensive Plextors are internally constructed. Then again, we would probably be surprised at how chintzy the inside of a $5,000 LCD TV looks.


The mods should probably make this thread a sticky, as I don't know if there's another one on CDfreaks that instructs the owner how to open their drive and remove the unit (with photos). All manufacturers should provide this information since the only people who will try it are techies who know how to build their own computers, and are smart enough not to open the case until it's off warranty. Lite-On's structural design certainly doesn't make opening the cover and pulling out the board easy. It's almost laughable that you have to use a screwdriver to bend and force the edges apart so that the case lifts out, and bend them back into place once the board is back in!


After I reattach the cables this afternoon and try another disk, I'll post again with the results.

WP-you're welcome. I used ms paint to add the circles cause I couldn't figure out how to do it with my very old version of photoshop (5.5).

I just used my thumbs to flex out the metal tabs so the chassis would drop out of the metal case. The tabs only need to move outwards by their own width so not much movement is required. That way nothing gets bent.

By accident, I found out that if I slide the drive rails all the way forward on the burner case, the drive will sit further into the bay in the computer. This seems to cut down on the dust that gets sucked into the drive, as there is a little more airflow around it.

Hardware manufacturers try to turn a profit on very low margins. They make their stuff as cheaply as they can get away with. Most stuff is made to go together quickly, and not to be taken apart or repaired. Probably their worst nightmare is having a consumer take apart their product.

The trend seems to be toward lower life expectancy for hardware. While the 1633s was rated at about 100,000 hours MTBF (mean time between failures), the 165H6s is rated at 70,000 hours. MTBF is a statistical projection based on a bell curve. Only a certain percentage of drives will reach the target hours. Some will last longer, others will fail sooner. (70,000 hours = about 8 years) I use the warranty terms, and mtbf, to get a rough idea of quality.

While the Plextor drives have the best scans I've seen, they also cost more. I stick with LiteOn because they offer the best bang for the buck. Also, the wide variety of utilities and firmware available from unofficial sources offer a greater degree of flexibility (thanks codeking etal). Plextors cost about twice as much; I doubt they are twice as good. They're better, but not that much better.

It seems to me that the quality of the media is the most important thing. I've always used +R media in my LiteOn. TY dvd+r and Verbatim 2.4-8x dvd+r dl burn well so I'll stick with those. Though I haven't ordered from them yet, rima.com has low prices on media as well as a good reputation. If you use ground shipping, keep in mind that heat is not good for your media. Best to order in winter. Those delivery trucks can get very hot in the summer.

Another caution on using lubricants inside your drive. Petroleum based products (like WD-40) will degrade plastics. Synthetic light body grease, like silicone grease, would be the best choice. Use sparingly. It's available in most hardware stores etc. as plumber's grease. Make sure the label states 100% silicone. Stay away from automotive products. Oils are not a good idea. No telling where they'll end up inside the drive.

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Last edited by Hoku; 07-01-2007 at 22:49.

But that 70000 hours would take eight years running
the drive 24 hours a day.

Yeah, but it's a statistical projection derived in a lab environment under ideal conditions. Cooling in your computer case is optimized for the mobo and processor, not the optical drives. Heat and moisture are the enemy of electronics. I even had an ant farm in my computer when I lived in Hawaii.

The drive might last long enough for the media format to become obsolete, which would make the mpaa and riaa very happy. I still have an old RCA videodisc player stashed in the attic. Some alien may show up with one of those discs off the Voyager spacecraft someday. You never know. %)

It took longer than I expected to post this message because I wanted to do a few scans first. I reinstalled the drive and started to burn a CMC DVD-r. After the initial lead-in was written, the drive powered down and I received a "power calibration error"!

That was the first time I saw that error on this drive, so I searched CDfreaks and found that the general solution was to take a deep breath and blow into the drive after opening the tray. I decided to go that route AND I reloaded the CS0T firmware as well as reset the learnt media using the EEProm utility.
(I wanted to cover all bases before I had to open the drive again and see if the lens had a smudge on it). I also checked the power connectors and IDE cable and made sure that Ultra DMA was the transfer mode for the secondary IDE channel. Everything was ok.

It's possible that the disk was causing the error as the 1633@1653s with CS0T firmware doesn't like -r disks. I used to get pretty good scans even with CMC -r's with the original BS0S firmware from Lite-On.


Here's are some scans after the lens cleaning. I used write speeds of 4x for both because my first post lens clean/post reflash try was at 8x for a Staple CMC Mag E01 +R disk. The quality score was 77 with a max PIE of 24 and a max PIF of 6. The total PIE's and PIF;s were 32610 and 610, respectively. Tha't not bad for CMC, but I didn't like the Q score. I decided to go with a lower speed for the first few scans until the drive relearns each media brand.

The first scan is a Staples CMC Mag E01 +R and the 2nd one is a Sony TY T02 +R. The drive loves this brand (as do most drives). I should have bought out the entire stock last year when Sony MIJ's were available. Even though the CMC scan is excellent (better here than the TY), my scans are consistently better with Sony TY's, whereas the CMC's change from batch to batch. However, considering I paid about $3 for a 50 pack CMC spindle (after coupon) at Staples last year, it appears to have been a pretty good buy!

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Last edited by WiltonParmenter; 12-01-2007 at 07:33.

As you can see, the first scans were pretty good, especially for this drive. I've had better with both brands, but the drive still needs a few more scans with all media brands.


I've noticed that most 16x +r media (other than Verbatim MCC004's) doesn't scan well on this drive (and the drive can't burn faster than 8x anyway).

The Mean Time Before Failure begs the question of time doing what?

Time sitting on a shelf.
Time sitting in the computer powered up but with no disc.
Time sitting in the computer with air gently wafting through and depositing dust.
Time reading a disc.
Time burning a disc.

I'm thinking if I want an optical drive to last a long time I would put it into an external enclosure. When it's powered off there should be little dust being deposited. But if the lens should get dusty, I will know what to do now