Lens cleaning for optical drives

Hi all

I've heard it suggested that wet cleaning works better than the cleaning CDs with little brushes - isopropyl alcohol was suggested; I have some here (use it for many things)

would appreciate views on this before trying it for real - are the lenses coated, and if so is the coating safe against that solvent?

TIA and best wishes, HJ.

 

Hugh Jarss--See the part on lens cleaning here
http://www.deinmeister.de/cdrep_e.htm
The title of your thread suggests you are interested in cleaning the CD-ROM's lens, not the CD, so I answered accordingly.

 

Hi Jim

thanks for the link - indeed it's the lens I'm trying to clean...

went to the page:

but it does lead to some good links at the bottom of the page though, particularly this one, from which:

it's the blue tinge that was worrying me, it looks rather like a coating.

will try carefully with pure isopropyl at the periphery of the lens first...

very best wishes, HJ

 

Hugh Jarss--Sorry you got conflicting advice.
But maybe it is not so conflicting. The link I provided was talking about a lens with dust on it. I suspect I would feel comfortable using compressed air (not aimed directly at the lens) to clean that, and being sure that I had not shaken the can--to avoid coating the lens with propellant). For oily smudges, then yes, maybe use something that requires contact with the lens.
But I gather you feel comfortable with at least one of the recommendations.
But, any particular reason for cleaning that lens? If it works, perhaps do not fix it.

 

no worries about the conflicting info, is what I was half expecting - the internet is a great source of information but is also a great source of mis-information...

So I try to compare a few sources - and the other reason for posting of course was hoping to hear from someone who has tried cleaning with isopropyl alcohol, to whatever result.

==

Samuel Goldwasser's page (the link in post #3) is an impressive resource, not dumbed down, not out of date. There's also a similar page for optical drives generally. (so Jim - once again, you have pointed me at a seriously useful link - although indirectly this time )

I have several optical drives here which might benefit from "wet" cleaning: one will clean up OK with a cleaning CD (w. brushes), but only stays working for a depressingly short time - I suspect there's some kind of oily film on the lens which is making the dust stick. (?tobacco perhaps - could be anything, it's 2nd user). I've never felt happy about scraping the dirt off with those little brushes anyway...

Also another couple of drives which have cleaned well enough to play some kinds of disc but not others - probably try one of these first because they are no good as they are.

But most of all my next door neighbours (who have 5 highly energetic children) have persuaded my to try to mend their Sony Playstation. Which didn't take much doing: without it working, our "normal" neighbourhood chaos level has reached manic proportions. There's something looking like strawberry jam involved...

best wishes, HJ

 

have now tried cleaning up a couple of drives - some notes:

isopropyl alcohol worked well; cleaning the objective lens (the one you can see) with this removed more than a cleaning CD does.

==

Going in deeper:
I took apart a couple of totally dead drives first to gain familiarity - to find as much (perhaps even more) dirt on the inaccessible parts of the optics as on the lens you can see (makes sense if a cleaning CD has been used beforehand, of course). Which is presumably why cleaning CDs (w. brushes) sometimes have little effect.

So I decided to disassemble a pickup assembly "for real" to clean the internals... this is not easy and requires correct tools, sensible working envronment, good dexterity & eyesight.

Considering the relatively low cost of replacement drives nowadays, fitting a new drive is undoubtedly a better bet.

==

There are variations in construction between different types of pickup, the following refers to a Sony KHS400C pickup assembly:

yes, you can get at more than the objective lens, but it's not for the fainthearted. The black cover surrounding the objective lens removes with three clips, to reveal 4 small crosshead screws. Taking these out allows access to another lens but! - there are problems:
1) the small screws (and your screwdriver!) are attracted to the (powerful) magnets;
2) the focus coil assembly connects with four thin wires. At the sled end of these wires there's something which looks rather like hot melt glue but it isn't - it's grease, rather like vaseline. And, it's very hard / impossible to take out the two screws at this end of the assembly without getting this stuff over the screws (and driver). Which doesn't render the operation impossible but does raise the difficulty level, particularly considering the darned things are doing their best to stick to the magnets...

getting this grease / vaseline on any of the optical surfaces is a clearly a very bad idea - thankfully I managed to avoid doing this

this provides access to the top surface of the other (?collimating) lens, but not the bottom of this lens or the turning mirror. This may be possible, but I could not readily see how to gain access without causing damage.

I cleaned the top of the collimating lens but didn't dare going further - as this alone had removed quite a substantial amount of dirt (easily visible to naked eye!), I reassembled the pickup and tested to see whether it had made a difference...

...and it had. The drive now performed much better than previously. I could now get audio CDs to work reliably every time. Unfortunately though, the intended purpose of this pickup is DVD... and it hadn't improved enough to get these working.

the bottom line (I suppose) is that there was far more dirt lodged on the internal optical surfaces than I was expecting

best wishes, HJ.

 

Hugh Jarss--Whew!! Thanks for sharing. Nerves of steel!!
The message I came away with is

 

HJ, don't tell me you've "given up"

My kids were not allowed to put a CD (in those days) in the drive without "holding" it correctly.
Jam/conserve/jelly...aaarrrggghhh!

Your endeavours...I think you have done well...tried and failed, maybe, tried and learnt a lot...you be the judge .

Matt
PS Samuel Goldwasser's site is good, I agree.

 

Hi Matt

this "giving up" thing - sometimes knowing when to "let go" is just as (or more) important than stamina or persverance... there comes a point when the only wise thing to do is "draw the line ".

...so of course I didn't (c'mon man what d'you expect?) and continued disassembly

managed to get to the other optical surfaces; again a black plastic cover; again, held on by clips - but this cover fitted much tighter than the top one, and without being able to see the clips was impossible to know which way to unclip them. Bent the cover a little prising it off - didn't matter, it "unbent" perfectly well

after this, removing one crosshead allowed a mini PCB to come loose, but it was still constrained by flexible printed wiring at both ends. It did afford enough freedom (~5mm) to get underneath though, exposing the lower surface of the ?collimating lens, and the turning mirror

access was difficult, these parts were too close together to get a cotton bud between, so toothpick+cotton wool job & Isopropyl again.

there was nowhere near as much dust on these surfaces. The lower black cover fitted quite tightly... whereas the upper cover had an appreciable air gap (to allow the objective lens freedom of movement); plus with the rotation of the CD there's appreciable air movement involved, carries the dust with it, gets in through the gap

==

I learnt lots! That grease stuff came straight from leftfield, never would have guessed that from looking at the pictures.

Isopropyl makes for a far better job than "cleaning" CD w. brushes, which I now regard as little short of lethal if used more than once. It's one thing considering their use if you only have a single drive. But share the "cleaning" CD around a few drives and you've cursed the lot of them.

Dust behaves very differently if there's been airborne oily contaminant involved - if that's the case the advantage of ispropyl is even greater.

==

Whether to try "diving in "? - has to be on individual merit. If the situation is borderline, and if it looks not too hard* then maybe yes - but the lower surfaces most probably aren't going to be worth the hassle.

*tried a few drives now, the pickups have been quite different in terms of how you "get in "

But mostly I wanted to get a bit of "hands-on" before having a go at the more precious drives, particularly a burner drive I'm quite intent on doing my best with. Although the story of the burner that packed up has just taken a new and quite unexpected turn...

I wish I could borrow you to drum some sense into my nephew. In-laws sent their Dell round, it had stopped working and was making an awful grinding noise. It's a hernia-inducing old beast which has a 5.25" floppy drive as well as a 3.5 "...

...didn't take a lot of mending, and I was also able to return to them the Rachmaninov piano music CD which had mysteriously vanished.

Somehow I don't think nephew had been holding the CD correctly when he put it in...


best wishes, HJ

 

Somehow I knew that was going to happen!

On the weekend I was installing a CPU. The instructions were to clean the old thermal compound off with isopropyl alcohol. I didn't have any at hand (only normal spirit which can leave a residue). Next to me I noticed a can of Contact Cleaner and used that (on a cloth). Worked magic.

Have you seen any comments about using Contact Cleaner on the lenses? I suppose it would "melt" greases from moving components that require the grease to work, so you would have to apply it with a cotton bud (Q-tip) like you said. Think it might work? I am finding more applications for it every day.

Matt

 

Hi Matt

if it's like the contact cleaner I have here (RS) then probably not a good idea for lenses - is intentionally designed to leave behind a small amount of oily film (recipe goes back to Strowger days)

best wishes, HJ.