NAD CD Player - How a CD player works ( laser unit replacement ).
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- čas přidán 5. 09. 2024
- This is a short video demonstrating the functionality of a NAD compact disc player, aka CD player. And steps to follow to replace the laser unit. In most cases the player will not read the disc when the laser is faulty and will display 'NO DISC'.
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AWESOME video, thanks. I’m trying to save my AIWA CX-800 made in 1990.... picked it up at Goodwill and it lasted me 5-6 years. Laser mech failed, then one of the tape decks and finally the DAT/AUX input. Held on to it another 4 years and am finally repairing, it’s a great machine.
Thanks for the compliments, and thanks for watching, Regards Hendri
Thank you so much for this video man! Picked up a “no disc” plagued NAD C515BEE for 10 bucks and your explanation about the solder point/ when to desolder during replacement helped a lot.
My youngest picked 16:13 up a c520 for £5.00 last weekend , as it wasn't opening up correctly.
Fixed it with a loomy band , as the little drive belt was worn...
Old hifi beats youtube any day.
Thank you for that lovely video. I love music and I like watching videos about CD players and record players - Freddie (age 4)
Very easy explanation thank you Sir
Great tutorial, managed to repair my NAD C 542 cd player (tray didn't come out). Many thanks
Hi Andrey, great thing to fix the tray-issue! What did you do? Belt exchange? My NAD c521i player is great working, exept ejecting the tray. Motor for the tray is working, but does not get any voltage when pushing the eject Button…
Do you have any idea?
@@peterstoeful In my case, the incomplete disassembly of the mechanism helped, as far as I remember, the whole thing was in the limit switch
I'm afraid it will hardly be useful to you,
best wishes
@@andreydavydov6417 ThX!
The laser looks like it's failed on my NAD S500 Silverline player ( a Mk2 1997 design that has a CDM12.4 transport made by Philips ).
I can get the disc drawer off and removed but the disc clamp/puck is held in place on a metal frame that springs up and down instead of the transport retracting downwards to let the drawer open with the disc. Any ideas on how to get the puck out and the transport out of the player casing?
The service manual available on-line is for the S500i improved model which uses a different Sony transport ( not a Philips CDM12.4 ) with a similar clamp to the one on your 502, and isn't screwed in place in the same fashion. On the Mk2 S500 the whole transport is suspended from two rails that run fore/aft and the securing screws face downwards underneath the rails making them almost impossible to get to without a special tool (a small allen key might work but I've no idea what type of head is on these screws as I just cannot see them, they face downwards to the bottom of the player - may have to get a dentists mirror to see them.
Can't remove the rails as they support the mains transformer and all the separate tappings to the analog, digital, control and output stages (all on separate boards) and I don't want to take the whole player apart, just the transport, so I can fit a new laser pick-up.
I have a marantz cd player i got no disc message. I tried cleaning the lens but it did no good. Could the lens still be bad if the laser lights up?
Many thanks for this post. My unit is "sticky." It plays fine, then will stop or skip. Any ideas?
Thank you, very good video.
Thank you too!
my spindle motor wont turn when disc is inserted and i press close.why?
The motor is either broken, or isn't getting any power.
In My luxman cd player,cd keeps spinning.not detecting the cds . Pls advise how to rectify . Thanks
Agreed. Thanks for the video. I also have a NAD 541 with a temperamental drawer not opening, and the laser not reading tracks or skipping as it tries to play. I thought I might be able to "clean" the laser and "oil" the drawer mechanism. Is it worth replacing the laser unit if the laser can be serviced? Any responses from any fellow NAD-ophiles are welcome.
Hey, if you still have it, you may find the drawer is stuck because one of the belts has degraded and become slack. Open the lid and study the CD loading, looking for slippage on the pulleys.
great vid but how do you adjust the laser's output (when it doesn't recognize a disc)/
You can't adjust the output (well you can try increasing the current but you'll just end up frying the chip that powers the diode so it's not a solution - it would be like running your car on Jet-A aviation kerosene, it will just blow up from the additional heat).
The laser is a semiconductor diode, and when it's stopped lasing it means all the electrons and holes in the doped P-N junctions have changed energy levels and the diode is effectively "exhausted" or dead. Much like a typewriter ribbon that has all the impregnated ink used up or a turntable cartridge stylus that's had all the diamond worn away.
The process usually takes a long time, typically a CD semiconductor diode has 10,000 hours of life which equates to a 10 - 15 year lifespan, but once the diode has stopped outputting light, that's it - game over.
The only solution is a brand new laser pick up fitted with a brand new laser. And a fresh 10,000 hours of life.
My NAD 5170 plays a cd and you can just barely hear the music and a pink noise static sound overshadows the music in right and left channels-can someone tell me where to start in diagnosis?
Almost certainly a compact disc with CD rot. I.e. the Aluminium reflective coating has oxidised and turned into dull non-reflective aluminium oxide. This was a common problem when the CD manufacturers failed to encase the aluminium with a resin top coat, leaving the aluminium to slowly oxidise from the disc edge inwards.
It ruined a lot of discs pressed by Du-Pont Optical at the Philips plant in Blackburn. If you're lucky, you've got a disc where the oxidation doesn't encroach onto the disc inner segment where the data is read from. If you're unlucky, the whole disc turns a dirty bronze colour and won't reflect any light back to the detector photodiode.
Thanks for the info-I’ll try a different cd and see if it makes a difference
Excellent video, thank you for posting. My unit, a NAD C541i, sees CD's, reads the table of contents, but wont' 'zoom' to play the specific track. I am assuming the 'slider' mechanism is stuck, or refuses to move up and down (along) the CD so as to play each specific track. Any ideas? How do I fix the 'slider' mechanism to enable the CD's laser to move to each specific track after reading the table of contents. Thank you. (sub'ed).
The laser focus might be broken (fairly common failure mode), but it's also possible that the laser tracking motor on your transport, or the "null" microswitch that locates the laser in it's "parked" position are faulty.
The laser beam is focused down to a small 0.9 micron diameter beam to read the pits which vary in length. The disc can be warped or misloaded by as much as 0.5 mm, and the focussing solenoid has to have sufficient movement to accommodate this. Hendri shows the focussing lens moving up and down. Your disc could be warped by more than this and it would exceed the compensation available in the focussing system. The main CD spindle could also have worn bearings, like an out of balance wheel, and it would be impossible for a laser to track the CD as the wobble will increase with the laser moving to the outer edge of the disc.
With the laser tracking across the disc itself - that uses a separate mechanism - either a radial arm like a record player conventional tonearm, or a rack and pinion like a parallel tracker tonearm. You can see Hendri moving the rack and pinion in the video. It's worth stripping the mechanism down, removing the dried up old grease with isopropyl alcohol and relubricating with fresh grease, as you would when servicing a mechanical watch. But if the motor or microswitch has failed, it's probably a brand new transport that will be required.
It's very unlikely to be a firmware or hardware (chip) fault, that would knock out the whole player and a power or magnetic surge would also take out any nearby equipment as well, not just the CD player by itself.
Is the player right next to a loudspeaker or CRT TV? If so, the stray magnetic field may be causing the problem, and preventing a hall-effect switch from working.
Thanks for the video, i have repair my NAD cd player myself. Very cool.
Good to hear, glad you did it your self. Best feeling to fix someting DIY. Hope to load more video's. Thanks for watching.
Need to know how to clean a CD player on Sony mini hi fi system model cmt cp 100
use fine cloth!
hello sir.are the lasers universal.
No.
Lasers are specific to individual transports. A Sony transport uses a different laser pick-up to a Sanyo, Philips or Toshiba.
DVD drives that can also read CD's as well are a whole different kettle of fish - they pack two lasers into one pick-up.
And then there's Blu-ray, using a third completely different wavelength of light.
CD uses 780 nanometres, DVD uses 650 nanometres and Blu-ray uses 405 nanometres, which, being violet, it should be re-named "violet-ray".
A CD only player cannot replay DVD's or Blu-ray discs because it's laser only emits 780 nm light. A DVD player might (or might not) be able to re-play CD's depending on the laser pick-up fitted, as the laser has to be multi-wavelength (essentially two separate lasers built into one laser pick-up, with a shared photodiode detector to measure the reflected light off the disc.
Most "Violet-ray" players are only able to replay that format, it's not physically possible to shrink 3 separate lasers (with their own wavelengths) into the available space.
'The thing gets very upset' at 7:58, very funny! 😆
Could you explain how to change the belt, please?. Thanks un advance.