Denon DCD920 CD Player Service Manual help

[Nevillet]

Hi all,

I'm trying to track down a service manual for a Denon DCD920 but am drawing a blank. Can anyone point me in the right direction?

Many thanks.

Neville

[R_J]

Re: Denon DCD920 CD Player Service Manual help

What do you actually need, as there is the schematic on the internet.

[Nevillet]

Re: Denon DCD920 CD Player Service Manual help

This CD had a non opening drawer which has now been lubricated and fixed.

It spins up a CD but I have no audio output or track details on the display.

I connected a scope to one of the test points which started it playing.

So i'm wondering if one of the adjustment pots needs tweaking - but which one?

[R_J]

Re: Denon DCD920 CD Player Service Manual help

No pots need to be adjusted, Did you find the schematic?

I connected a scope to one of the test points which started it playing.

It might be more help if you said WHICH test point you touched.

[Nevillet]

Re: Denon DCD920 CD Player Service Manual help

Just brought it back to the bench and I can't seem to repeat the phenomena.

I'm pretty sure I touched the FEO pin on TP101.

It doesn't want to play or read the TOC.

The CD spins. No disk data is displayed. Occasional focusing? heard.

[R_J]

Re: Denon DCD920 CD Player Service Manual help

Do you get any eye pattern on tp102-1 (HF)? I would check that the spindle motor is not sticking and spins freely. if it spins slow it might not read. You did clean the lens ?

[Nevillet]

Re: Denon DCD920 CD Player Service Manual help

Yes I've cleaned the lens.

When it did play the speed seemed 'normal'

Below is the trace from tp102-1 (HF)

[R_J]

Re: Denon DCD920 CD Player Service Manual help

That waveform is not very good, that's why its not reading, Have you checked that the +&-5v and +&-10v are ok and clean.

[Nevillet]

Re: Denon DCD920 CD Player Service Manual help

I measured the +/- 5V at the regulators and they are both stable and on target.

I need to take a closer look for the +/- 10V rails. There were no obvious regs like the 5V ones.

It's a bit late here and my bed beckons. Back tomorrow.

[R_J]

Re: Denon DCD920 CD Player Service Manual help

I measured the +/- 5V at the regulators and they are both stable and on target.

I need to take a closer look for the +/- 10V rails. There were no obvious regs like the 5V ones.

It's a bit late here and my bed beckons. Back tomorrow.

The +/- 5 volt regulators are supplied by the +/- 10 volts, so check the input to the regulators, Since you have a scope, check the ripple as well. The +/- 10v supplies the spindle motor drive.
I assume you have the schematic.