NAD CD C541 display is fading

[hreiff]

I have a C541 cd player, where the display is fading - ie. it is difficult to see track and time - except from that it is working fine.

Any ideas what to look for, or does anybody have a service manual with diagrams ?

No potentiometers to see on the board.

 

[docfin]

Service manual for NAD C541 available here: http://service-manuals.webs.io/

 

[Finnegann]

I have the same problem with 2,5 years old 541i. I think it's a fault of the display itself.

 

[es44]

In some of Nad's displays are tiny light bulbs, which i have succesfully replaced with hi brightness led's. (remember to use a series resistor).
In other of their displays there's a thin piece of plastic with "built-in" light, i don't know the name of it 🙁 .

Servicemanuals of both c541 and c541i can be found for free here:
Manuals
Good luck
Ebbe

 

[tubenut]

LEd replacement can work but tends to cause hot spots, ie areas of the display that are brigheter unless you use a very bright LED pointing away from the display perhaps and only use reflected light.....

Though replacing the bulb seems trivial, you do need to almost strip the complete machine. Stupid design imo. I understand LCD being lower noise to fluor type but the bulb should be easier to replace.....

 

[es44]

LEd replacement can work but tends to cause hot spots, ie areas of the display that are brigheter unless you use a very bright LED pointing away from the display perhaps and only use reflected light.....

I've had no problems of this kind. I always sand the Led, so the light is more diffuse, and at the same time taking care of not pointing the tip right towards the display.
13.000 mcd Led's works really nice 😀

Best regards
Ebbe

 

[hreiff]

The 541 have a VFD (Vacuum Flourescent Display) - No bulbs.

It seems to be to power supply - Voltage is too low.
I am working on it at the moment.

 

[hreiff]

Found the error.

NAD are using a voltage doubler at the power supply for the display - which means if (when) the capacitors lack capacity, the voltage drops to half the value - ie. the display is fading.

I changed the two 100 uF capacitors (C560+C561), and the problem was solved.

 

[es44]

Great to hear some feed-back, so others with the same problem has a chance to narrow down the fault searching 😀

Mange hilsner 😉
Ebbe