Translate

Friday, 14 October 2016

NAD 5425 CD player - no display

Just a quick one. This delightful NAD 5425 CD player.



Arrived skipping / not reading discs and no display.


Skipping and intermittently not reading discs was an easy fix, a quick clean up of the optics with an airduster, and very careful cleaning of the lens (DON'T USE IPA HERE! - it can damage the optical coating on the lens. It's easy just to breathe on it, and give it a gentle wipe with something lint-free). That had it playing even the most mangy looking disc!




No display?



Let investigate...

The main board is removed ....









.. and the display cowl removed (there's a couple of screws underneath, and a plastic clip.)












... and an open-circuit incandescent lamp is the culprit...










To improve reliability, and LED and 1K limiting resistor is fixed in place. Note the capton tape to insulate it electrically from the links on the board below. Anode (+ve) is to the right in this picture.

The LED I chose was a wide-angle, warm white LED, which I hope will match the original incandescent lamp closely.







... which is does nicely!














I've not tried these wide-angle LEDs before. They're quite good. These are both warm white examples, although they differ in colour slightly! You can clearly see the focussed "beam" coming from the right hand LED, and the much more diffuse spread of light from the left hand "wide-angle" LED.





Job done. Another saved from landfill!


11 comments:

  1. Great post, so nice and clear and concise. Just bought one of these players off of eBAY because it is 'dead'. I'm hoping its just the display bulb!

    ReplyDelete
    Replies
    1. Hi John. Another thing that causes these to appear "dead", is dry joints around the voltage regulators... Hope it goes OK! Be safe. Andy

      Delete
    2. Thanks Andy, I will let you know what I find!

      Delete
  2. Well it was dead because both internal fuses were blown! Bulb also gone but before I sort that I need to work out why it does not read the disc! May have bought a bad one!

    ReplyDelete
    Replies
    1. How's the soldering round the voltage regulators? Does the mech click-click-click when a disc is first inserted?

      Delete
  3. Definitely at least one bad joint. I have ordered a new laser for £5 so that I know it's OK. Will solder poor joints, fir LED and resistor and new laser and see what happens - awaiting parts as I type!

    ReplyDelete
    Replies
    1. ... if that's an eBay laser, best of luck with it. Got sick and tired of sending them back....

      Delete
  4. Actually I went for one from CPC manufactured in Japan rather than China!

    ReplyDelete
  5. Well in an ironic twist I have everything working now except the backlight! Im only getting 0.5v across D505. I have recheck joints around voltage regulators and cant see anything wrong. Sound output is lovely. Play mechanism is spot on!
    Any ideas?

    ReplyDelete
  6. By the way, the reason it didnt read discs was that the prevoius have a go hero had plugged the blue and red connectors back into the main pcb the wrong way round!

    ReplyDelete