AKAI Stereo set AX-M430 No CD Audio out

[BRASTO]

This (old) stereo system works fine when using Tuner, Tape or Phono.
The problem is when using the CD player which has an Optical link
only. (Link is established correctly as shown by flashing indicator
turns steady after 4 seconds of disk operation)
The sound of the CD player can only be heard very very weak from
headphone or speakers. (Volume rotated to max.CW)

Using some basic troubleshooting technique by probing with the
oscilloscope,I have established that the CD signal gets thru the
optical link unattenuated. It is DA converted somewhere and I have
noted the presence of good analog audio levels at two Caps (Left &
Right audio present)..

It looks like that the audio is not switched correctly/completely to
the Final Audio amp. (permanent mute ?)

Normally some digital IC will do that job, but not having the AKAI
schematic I have been unable to trace its circuits.

Anybody who can help ?

TY
Brasto

 

[Meat Plow]

This (old) stereo system works fine when using Tuner, Tape or Phono.
The problem is when using the CD player which has an Optical link
only. (Link is established correctly as shown by flashing indicator
turns steady after 4 seconds of disk operation)
The sound of the CD player can only be heard very very weak from
headphone or speakers. (Volume rotated to max.CW)

Using some basic troubleshooting technique by probing with the
oscilloscope,I have established that the CD signal gets thru the
optical link unattenuated. It is DA converted somewhere and I have
noted the presence of good analog audio levels at two Caps (Left &
Right audio present)..

It looks like that the audio is not switched correctly/completely to
the Final Audio amp. (permanent mute ?)

Normally some digital IC will do that job, but not having the AKAI
schematic I have been unable to trace its circuits.

Anybody who can help ?

Mechanical switching between other modes?

 

[BRASTO]

Mechanical switching between other modes?- Tekst uit oorspronkelijk bericht niet weergeven -

- Tekst uit oorspronkelijk bericht weergeven -

Yeah, could be in that area, but the system does not switch
mechanically between modes, it does this electronically by the push of
a button...I have to find out which components are doing that
job....But still no schematic available and ther last thing I 'll do
is buying the service manual.....

 

[JR North]

If your serious about fixing it, that's usually the first thing you do...
JR

BRASTO wrote:

But still no schematic available and ther last thing I 'll do