Question about NAD L40 CD Player

2 Answers

High pitch sound even with speakers disconnected

My NAD L40 is about 5 years old, and it works fine, but since a month or so it has been making a high pitch sound whenever it is turned on, the sound is not very loud, but it is annoying. I have even unplugged the speakers and everything connected to the receiver (aux input), and the sound is still there. This is regardless of the input (CD, AUX, TAPE, TUNER).


Posted by on

2 Answers

Re: High pitch sound even with speakers disconnected

Hi Naduser,
I hav had the same problem (probably). It is a smal chopping powersuply to power the backlight of the lcd-display. It's a small pc-board mounted at the rear of the cd-cabinet, just next to the mains-power-transformer. It can be easyiely disconnected by unplugging the 3-pole connector from the mother-board, and the sound will be gone. However the display readout will faint down then, but its still readable. The higher serial-numbers don't have this problem, so an exchange of the small pc-board might be the best solution.

Succes, Hildert

Posted on Feb 03, 2008

  • Level 2:

    An expert who has achieved level 2 by getting 100 points


    An expert that got 5 achievements.

    Vice President:

    An expert whose answer got voted for 100 times.


    An expert who has posted more than 50 answers, of which 90% or more were rated as helpful.

  • Expert
  • 108 Answers
Re: High pitch sound even with speakers disconnected

1.the problem with your audio processing circuits and improper power filter
2. Check audio amplifier coupling capacitors
3. Rectifier capacitors
4. contact service centre

Posted on Dec 22, 2007

Add Your Answer

0 characters

Uploading: 0%


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


3 Points

Related Questions:

1 Answer

Hi. Hope you can help me out here. Some1 is offering to sell me his NAD C521i CD player. Its been with him for 5 years. Is it wise to get it since it is already 5 years old (at least that i what the guy is...

This cd player sound great but have in mind it is fitted with NE5532 op amps in linedriver stage, but single trafo supply, and this player is a standard production line cd player. I owned one, i liked the NAD sound, and i think if you pay something like $100-$130 you will be happy. Also you ask if you shall be aware of something, in older nad cd player displays is sometimes defect, but easy to fix. Also the laser need to be adjusted often. (as in most cd players.)
Step from track 1 to the last traack fast and back to track 1 again, listen to music parts from track 1, track 4, track 10 track xx.
If the sounud is not choppy, if there are coming sound in both speakers and otherwise it sounds good then i think you can buy it without expecting major problems.

Oct 03, 2011 | NAD C521 CD Player

1 Answer

Have had this Nakamichi CD player since 1991. Recently there's a high-pitched hum with no music playing. The changer works fine-just no music.

Model number? If it uses analog audio cables you might have a noise leak from improper shielding. Reseat the cables or try new ones.

I'd also consider if you're using dimmer-controlled lighting in the room. They generate a lot of electronic noise. I never solved my problem with them even with a new dimmer so I just don't use them while listening.

Feb 20, 2011 | CD Players

1 Answer

Cracking sound in high frequences when playin right cahanel only

u might not have any problem in cd player as per as my concerns i think u have normal speakers or a woofer they both are made for normal frequencies or low freq. respectively If u want good sound for high freq. u need to get twitter (chiller)
Or this may because of faulty right channel wire

Feb 27, 2010 | CD Players

1 Answer

NAD C521i four year old. Usually fails to find cd's When it does tracking and sound is bad.

I've dealt with this type issue quite a bit.
Believe it or not the drawer belt needs to be changed.
If the drawer isnt drawn all the way into the unit...the disc motor wont spin and get rejected
Also the lens on the laser could be dirty.

Take it to a tech . Try a local stereo store . They should know who's best.

Happy new Years,


Dec 11, 2008 | NAD C521 CD Player

1 Answer

Nad c520 high pitched ringing

Hi, From your description, it sounds as if the noise is coming from the circuit that controls the display backlight. If I recall correctly, the C520 has an EL backlight just like the C521 (which I have one of). On the front of the circuit board, there should be a little yellow trimmer potentiometer that controls the brightness of the display. It may be that the noise will go away if the brightness is turned down some. If  the noise varies as you turn the controller, but doesn't go away completely, the backlight may need servicing.

Aug 06, 2008 | NAD C521 CD Player

1 Answer

Sony rcd w500c recorder

Higher laser power is needed for high speed dubbing - does it work ok at normal speed? If so would point to a failing laser. Sony charge a lot for these but in the US there may be a fixed fee out of warranty repair cost.

Nov 03, 2007 | Sony RCD-W500C 5-Disc CD Recorder

1 Answer

Won´t read any Disc

I have the same problem since the early beginning after purchase. I'm very upset with NAD for the zero-value technical service in Italy. After 2 months they gave me back my C541 with new defects (the tray now doesn't work properly). They have tried - they said - different optics without fixing the problem. Does anybody know if a compatible optic / tray exists?
Thank you

Sep 25, 2007 | NAD C541 CD Player

4 Answers

Nad C542 Troubleshooting

found same problem with mine, solution .. place clean paper over the optic, then a magnet, leave for a few seconds, the build up of static causes a magnetic field in the optic preventing it tracking, have cured a few other brands with this as well .. shows manufactures are putting inferior parts in to their players, hope this helps !!

Mar 20, 2007 | NAD C542 CD Player

1 Answer

No disc

Try using a cleaning disc, if that doesnt work take apart the unit and manually clean the lens. If that doesnt work your going to have to take the unit in for an estimate. If its more then two year old and you paid less then 150 bucks for it , it probably is not worth the estimate fee. good Luck

Aug 26, 2006 | NAD C542 CD Player

Not finding what you are looking for?
NAD L40 CD Player Logo

Related Topics:

289 people viewed this question

Ask a Question

Usually answered in minutes!

Top NAD CD Players Experts

The Knight
The Knight

Level 3 Expert

66384 Answers

Robert Rankin

Level 2 Expert

338 Answers


Level 3 Expert

6993 Answers

Are you a NAD CD Player Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides