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Restoration of NSM4202 NSM4002 displays founded in Philips CD Players

This post is about the restoration of good old Philips CD Player’s display. In the 80’s, Philips released some types of players which utilized the National Semiconductor’s low pin count LED display: the NSM… series type. In this device there is a 35 bit shift register, and a LED driver, so it was easy to interface to system controller with 2 or 3 wires.

Unfortunately this display device is hard to find nowadays, and after 20-30 years, broken easily. (first just some of the segments, later all of the segment go dark.)

My goal was to keep the original look and feel of my Philips CD371 CD Player’s display, so i decided to disassemble the NSM4202 device to wire each led segment individually, and drive with external circuity. I was thinking that it is easy to implement the original function with a small microcontroller, with time multiplexed LED driving, but the original device is not time multiplexed (not flickered), it has steady and static light. So i looked, and find an excellent device, which has the original functionality for about 5 euros. (ST and MICREL is  same)
This device is: Micrel’s MM5450.

…to be continued…

– UPDATE 2011 december 30 – I uploaded a small pdf to show some information about wiring and correct pinouts. You can download here:
NSM4202 or NSM4002 display clone

http://www.youtube.com/watch?v=KivqSCVOFFs

http://www.youtube.com/watch?v=DX2OHoBwQPw

9 Replies to “Restoration of NSM4202 NSM4002 displays founded in Philips CD Players”

  1. Hi!

    Thank you for this tip!

    I am interested in doing this mod on my numerous Philips players (from CD202 to CD160).

    I wonder what is the datastream sequence.. Could you please help me?

    Thanks a lot, and best regards from France.

  2. Dear Denis

    Yes, i will look for my notepad for datastream. It was a sketch only, so i have to find it 🙂

    I will publish soon!
    Regads!

  3. Szervusz!
    Gratulálok a javításhoz!
    Nekem pillanatnyilag 2 lejátszómban is ez a hiba.
    Egy kérdésem, viszont lenne.
    Az átalakított áramkörről, egy kapcsolási rajzot, lehet kérni?
    Üdv: Ignász

    1. Szia
      A cikkben lévő pdf alapján nagyon egyszerű az utánépítés, minden benne van, csak a +5V -ot kell még az IC-nek megadni. Persze jó ha megvan a MM5450 adatlapja is, de az szintén megtalálható a neten. Majd megpróbálom lerajzolni is, ha így nem megy. Sok sikert kívánok!

  4. Hi, I have an old Philips cd160 with the same display problem. Could you post the schematic fo the new circuit wich drives the display ? Thanks.

    1. Hello, in the post, there is a pdf, in that there is all info to build the driver. You can also find the MM5450 datasheet on the net. 🙂 Best wishes!

  5. Helló, ez már jó ideje tudja javítani a kijelző NSM4202a, én is ugyanaz a probléma, azt szeretném megkérdezni, ha nem lenne az sematikus.
    Köszönjük Vaculik

    Hello, it’s been quite some time since you repair the display NSM4202a, I have the same problem, I want to ask if it would not schematic.
    Thank Vaculik

  6. Hello, it’s been quite some time since you repair the display NSM4202a, I have the same problem, I want to ask if it would not schematic.
    Thank Vaculik

    Helló, ez már jó ideje tudja javítani a kijelző NSM4202a, én is ugyanaz a probléma, azt szeretném megkérdezni, ha nem lenne az sematikus.
    Köszönjük Vaculik

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