Question about Denon DHT500SD System

3 Answers

Denon 500SD dvd wont play

How do I clean the optical pickup assembly lens?

Posted by on

3 Answers

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    Superstar:

    An expert that got 20 achievements.

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

  • Master
  • 2,071 Answers

Manually cleaning the lens
To locate the laser lens, look around the door or drawer of the DVD player and you will see a small circular disc, which is often called the turntable or disc platter. Right off the edge of the platter you should see a small clear lens. There are some manufacturers that have had problems with the lens, depending on the age of the unit. In these problem players, moving the unit to a different location, turning the unit upside down, or sometimes even without moving the unit, the lens can become detached from the laser assembly and floats around inside the unit. You can re-glue it back with a little crazy glue, BUT it must be perfectly centered, and without getting any glue on it. So, if you don’t see the plastic lens, but instead see the laser pick-up assembly, look around for the lens inside the unit and glue it back on.
To clean the lens you must use very little pressure. Take a cotton swab and barely moisten it with plain, non-scented, or oily type alcohol. In a swirling motion, very gently rub the lens until you’ve covered it entirely. Then repeat using the dry end.
If the cleaning didn’t help, don’t despair just yet. You can see if there’s a problem elsewhere in the unit by using a few simple tricks and tips.
First thing you want to see if the unit’s laser is in good working order. This method isn’t foolproof, but most of the time works admirably. When you insert a disc, see if you can look up underneath where the disc sits on the turntable. Observe the laser lens going up and down. If the lens is trying to focus, that’s good! After a few seconds of the lens trying to focus, the platter should start to spin. On almost every CD/DVD unit I've encountered, the unit won't spin unless the laser has properly focused on the surface of the disc. If the unit spins up and and then shuts down, you should check and make sure the laser pick-up assembly slider mechanism is working without any obstructions and that the small chrome rail that it slides on is slightly greased. Don’t go overboard with the grease though, as too much can cause all sorts of problems.
The slider mechanism, depending on the age of the unit and the manufacturer, consists of the small chrome rail, a drive motor, a small gear assembly, and (in some units) a small belt that drives the slider unit via the motor. This small belt causes all sorts of problems. If the belt is broken or slipping, it can cause skipping, dropouts, or simply no start up at all. Also, if the belt breaks in the middle of the disc, the drive mechanism gets hair or dirt wrapped up into the gears, or the pick-up assembly doesn’t return to the start position (called home), the unit will (99% of the time) refuse to release the disc, causing it to become stuck inside the unit. There’s a little micro or leaf type switch located at home position that sometimes gets dirty or breaks and, causing this problem also.
If the disc starts to spin slowly and doesn’t come up to speed, the spindle motor that’s attached to the turntable platter is a common problem. There could also be a problem with the spindle motor driver controller IC or the power supply regulator that supplies voltage to the driver IC. If the disc starts to spin and then spins really fast, or stops and starts to spin backwards, your problem is the laser pick-up assembly or the servo control circuit. If you continue to have problems after cleaning and checking the other things listed above, you may have a problem with the player's alignment. Of course, one of the problems you'll face checking alignments on a DVD/CD player is that you’re going to need to use an oscilloscope on most of them. If you have the proper tools and equipment, the first thing to look at is the RF pattern of the unit while its playing. It should be a sharp and clear pattern. If it's dull and smeared, then the laser could be weak.
Also, in these units are very critical alignments called the focus/tracking gains and offsets. When these alignments are off, it can often cause intermittent troubles. As the unit ages and parts change value, so do these alignments, and will need to be checked. In my time as service technician repairing DVD/CD players, 65% of the laser pick-up assembles I have tested were good and only needed a small adjustment. Today's technology makes it unfeasible for a shop to hook up a DVD/CD player, and even some recorders, to their equipment and make these adjustments because of the cost involved.

hope this may help;


DON'T FORGET TO RATE;


Regards,
VOTIT

Posted on Jan 11, 2009

  • Level 2:

    An expert who has achieved level 2 by getting 100 points

    Hot-Shot:

    An expert who has answered 20 questions.

    Corporal:

    An expert that has over 10 points.

    Mayor:

    An expert whose answer got voted for 2 times.

  • Expert
  • 57 Answers

Open the cover of your dvd player,then get your hair dryer and turn on the hair dryer and clean module board.after that get some 1pc of cotton buds try to clean gently the lens 3 to 5 times.then returned the cover .and turn the unit.

i hope it will work.

kira_ryuk@yahoo.com

Posted on Jan 11, 2009

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

    Vice President:

    An expert whose answer got voted for 100 times.

  • Master
  • 827 Answers

Hi,

You use a Lens Cleaner such as those advertised on this eBay link:
http://shop.ebay.co.uk/items/_W0QQ_nkwZdvdQ20lensQ20cleanerQQ_armrsZ1QQ_fromZR40QQ_mdoZ

Hope this helps

Chris (ziraffa)

Posted on Jan 11, 2009

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

Dvd wont play is something wrong with the lens


You have a bad Optical Pickup(laser).

Dec 28, 2014 | Home Theater Systems

1 Answer

"PROTECT" appears on my DENON DHT-500SD


Sounds like a speaker wire is shorting against either another speaker wire or something metallic. Check your speaker wires to make sure they're not shorting (touching). If that doesn't work, I'd take it to a repair facility. Good luck!

Feb 16, 2010 | Denon DHT500SD System

1 Answer

My denon adv 500sd wont read the discs can anyone help


If your unit has some time on it it probably has a dirty lense on the laser assembly. This isn't difficult to clean but you must exercise care not to damage any components of the laser assembly. Unplug the unit. Remove the top cover. If the disc drive has a cover, remove it. You should see the lense, looks like a fish eye, looking up at you. The lense is monted on a set of springs and will move around as you clean it. This is normal but do not apply anymore pressure than necessary. The alcohol will do the work loosening the dirt. Using 200 proof grain alcohol, available from any electronic parts supplier (www.mcmelectronic.com) and commercial grade, lint free, cotton swabs, also available at MCM, moisten swab and gently touch the lense rotating the swab head. Use a dry swab after the wet one. Blow dry the assembly with canned air, also available at MCM. Reassemble unit and you should have a working player. If you still are not reading discs you could have a defective or weak laser assembly. This would have to be replaced with a new unit. I hope this has helped you. Let me know if you need any more assistance.

hardrocko

Thank you for using FixYa

Feb 13, 2010 | Denon DHT500SD System

1 Answer

Denon DHT-500SD system and want what is on TV to come through 500


You could try the optical route. You should be able to use the analog RCA audio outputs of the TV to the analog TV or VCR audio inputs of the receiver as well. Select the appropriate input on the receiver and you should have TV audio.

Jan 02, 2010 | Denon DHT500SD System

1 Answer

DVD GO FORWARD BY ITSELF


Hi,
Do you mean DVD jumps / skips forward in playback?
If yes, please clean optical laser lens in player. It sounds optical lens has thin layer of dust and causing ' tracking error ' in playback.
Put CD Lens Cleaner disc in player and press play to clean optical lens by cleaning disc and if problem still exist, need to clean lens manually with good quality cotton bud.
Hope this will solve your problem.
Thanks.

Sep 08, 2009 | Samsung HT-Q100 System

2 Answers

I can play cd's ok, but not dvd's.


This is a classic sign that either the lens is dirty or that the optics are starting to fail. If you can get access to the optics assembly, try carefully cleaning the lens using a coton swab and alcohol. If that does not resolve the problem, the optics will need to be replaced.

Dan

Dec 31, 2008 | Aiwa XR-DV700 System

2 Answers

Denon DHT-500SD - DVDs wont load


the problem may be two fold
1 the optical pickup assembly's lens may be dirty and needs to be cleaned (donot use any liquid to clean the lens just a soft cotton swab will do)
2 the optical pickup assembly has failed and can no longer read discs (if the laser or sensors inside the optic fail it is "blind" and can not "see" the disc)
start with the cleaning.

May 25, 2008 | Denon DHT500SD System

1 Answer

Bad Disc


If you sure that the system supports the disc's format, the disc is clean, and its the right region.. try to clean the DVD lens. DVD lens cleaning discs: Every CD, stereo equipment, department, discount, store - and even sidewalk venders - carries CD lens cleaning discs. Are they of any value? Can they cause damage? I generally don't consider CD lens cleaning discs to be of much value for preventive maintenance since they may just move the crud around. However, for pure non-greasy dust (no tobacco smoke and no cooking grease), they may not hurt and could even do a good enough job to put off a proper cleaning for a while longer. However, it's also possible they will ruin the lens. Consider that the worst thing to do to a precision optical surface is to wipe it with a dry cloth as this is likely to scratch the surface as it rubs the dust over it. To the lens, a speck of dust is like a boulder. Once the lens is scratched, replacement of the entire optical pickup is the only remedy. And, since there are absolutely no sorts of standards for these things, it is possible for a really poorly designed cleaning disc to damage the lens even if the dust itself is non-abrasive. In addition, if the cleaning disc doesn't look like a CD to the optical pickup or disc-in sensor, the lens it may not even spin. So, the drawer closes, the drawer opens, and NOTHING has been accomplished! (But at least no damage will be done.) As if this isn't enough, NEVER put one into a high-X CDROM (DVD player or DVDROM drive). The high speed rotation may cause the cleaning disc and/or player/drive to self destruct. And, don't try a cleaning disc on an automotive CD player that sucks in the disk - it will get stuck.

Dec 20, 2005 | Emerson AV301 System

1 Answer

DVD won't play


Is this happens on every disc? The NO PLAY message appears when "The disc that this unit cannot play is loaded (from the user guide)". Maybe it's something to do with the DVD region? If you sure that the system supports the disc's format.. And it won't play other discs... try to clean the CD lens. CD lens cleaning discs: Every CD, stereo equipment, department, discount, store - and even sidewalk venders - carries CD lens cleaning discs. Are they of any value? Can they cause damage? I generally don't consider CD lens cleaning discs to be of much value for preventive maintenance since they may just move the crud around. However, for pure non-greasy dust (no tobacco smoke and no cooking grease), they may not hurt and could even do a good enough job to put off a proper cleaning for a while longer. However, it's also possible they will ruin the lens. Consider that the worst thing to do to a precision optical surface is to wipe it with a dry cloth as this is likely to scratch the surface as it rubs the dust over it. To the lens, a speck of dust is like a boulder. Once the lens is scratched, replacement of the entire optical pickup is the only remedy. And, since there are absolutely no sorts of standards for these things, it is possible for a really poorly designed cleaning disc to damage the lens even if the dust itself is non-abrasive. In addition, if the cleaning disc doesn't look like a CD to the optical pickup or disc-in sensor, the lens it may not even spin. So, the drawer closes, the drawer opens, and NOTHING has been accomplished! (But at least no damage will be done.) As if this isn't enough, NEVER put one into a high-X CDROM (DVD player or DVDROM drive). The high speed rotation may cause the cleaning disc and/or player/drive to self destruct. And, don't try a cleaning disc on an automotive CD player that sucks in the disk - it will get stuck.

Dec 18, 2005 | Yamaha DVX-S100 System

Not finding what you are looking for?
Denon DHT500SD System Logo

526 people viewed this question

Ask a Question

Usually answered in minutes!

Top Denon Home Theater Systems Experts

Dennis McCollum

Level 2 Expert

137 Answers

Electro Med Services...
Electro Med Services...

Level 3 Expert

5653 Answers

The Knight
The Knight

Level 3 Expert

68352 Answers

Are you a Denon Home Theater System Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...