Sony CDX-C5000 head unit, TUX-020 tuner module failure
 

Hi.

I have 2 Sony Car Audio head units both with faulty tuner modules. The
module is labelled TUX-020, and is listed online simply as "mounted
circuit board", it is also no longer available. I am able to get
schematics for the main unit, but this does not include any details of
the tuner block at all. I suspect Sony regarded it as a "black box".

One of the units tunes to AM stations fine, but FM reception is
extremely faint, barely audible behind the background noise. The tuning
voltage does sweep when I do a seek, and since the local stations are
faintly audible I suspect some failure in the front-end.

The second unit does not tune at all, though noise is present and
changes when an aerial is inserted. On this one the tuning voltage
remains high and does not sweep at all, obviously no reception on any band.

Car aerial has been confirmed good with a working unit. I have swapped
the tuner modules between the head units and the fault travels with the
module, confirming that the fault is with the module itself.

Does anyone have a schematic for this module? Failing that does anyone
have an old head unit with a good module (possibly one with a faulty CD
mechanism or output stage)? Or possibly some idea of where to start
fault finding? There are a lot of models from this vintage (around 1999)
which appear to use this module. If it's any help in identification, the
unit is a face-off with CD/MD changer control.

I would just buy a new head unit, but I have a 10 disc CD changer fitted
to the vehicle which is in good working order.

Sony CDX-C5000 head unit, TUX-020 tuner module failure
 

Clyde wrote in message
...
Hi.

I have 2 Sony Car Audio head units both with faulty tuner modules. The
module is labelled TUX-020, and is listed online simply as "mounted
circuit board", it is also no longer available. I am able to get
schematics for the main unit, but this does not include any details of
the tuner block at all. I suspect Sony regarded it as a "black box".

One of the units tunes to AM stations fine, but FM reception is
extremely faint, barely audible behind the background noise. The tuning
voltage does sweep when I do a seek, and since the local stations are
faintly audible I suspect some failure in the front-end.

The second unit does not tune at all, though noise is present and
changes when an aerial is inserted. On this one the tuning voltage
remains high and does not sweep at all, obviously no reception on any
band.

Car aerial has been confirmed good with a working unit. I have swapped
the tuner modules between the head units and the fault travels with the
module, confirming that the fault is with the module itself.

Does anyone have a schematic for this module? Failing that does anyone
have an old head unit with a good module (possibly one with a faulty CD
mechanism or output stage)? Or possibly some idea of where to start
fault finding? There are a lot of models from this vintage (around 1999)
which appear to use this module. If it's any help in identification, the
unit is a face-off with CD/MD changer control.

I would just buy a new head unit, but I have a 10 disc CD changer fitted
to the vehicle which is in good working order.


From my experience on
http://www.divdev.fsnet.co.uk/repair5.htm
probably not the TUX but some sort of firmware problem or a problem on the
front panel if its like those Sony XR-C5300
cant help more than that , its a "repair" job that got away

Sony CDX-C5000 head unit, TUX-020 tuner module failure
 

Hi!

From my experience onhttp://www.divdev.fsnet.co.uk/repair5.htm
probably not the TUX but some sort of firmware problem or a problem on the
front panel if its like those Sony XR-C5300
cant help more than that , its a "repair" job that got away

A friend of mine was repairing a radio using a similar TEA-series IC.
I don't recall the exact details, but the IC "seemed" to be doing most
of the right things while reception just never happened. When audio
did come through the set, there was a lot of hash and other noise in
the signal. Every other piece of circuitry checked out.

He replaced the IC and the radio sprang immediately back to life.

William

Sony CDX-C5000 head unit, TUX-020 tuner module failure
 

On 15/10/2011 17:49, William R. Walsh wrote:
Hi!

From my experience onhttp://www.divdev.fsnet.co.uk/repair5.htm
probably not the TUX but some sort of firmware problem or a problem on the
front panel if its like those Sony XR-C5300
cant help more than that , its a "repair" job that got away

A friend of mine was repairing a radio using a similar TEA-series IC.
I don't recall the exact details, but the IC "seemed" to be doing most
of the right things while reception just never happened. When audio
did come through the set, there was a lot of hash and other noise in
the signal. Every other piece of circuitry checked out.

He replaced the IC and the radio sprang immediately back to life.

William

I have to say I am suspicious of the i.c, as initial comparisons between
the 2 modules don't show any notable differences in component values.
The i.c itself seems to handle virtually everything aside from the tuned
circuits. I am suspicious that I have 2 faulty chips, one with an RF
amplifier or AGC fault or something along those lines, the other with a
fault in the tuning section.

I may well see if I can grab the i.c. and try it if it's cheap enough.
It may be difficult soldering up since there are quite a few large
components around it, which may make access awkward.

Thanks for the info

Sony CDX-C5000 head unit, TUX-020 tuner module failure
 

Most Sony radios with CD changer function will run most Sony CD
changers regardless of the models, as long as the interface cable
matches both.
JR

On Sat, 15 Oct 2011 10:26:47 +0100, Clyde
wrote:

Hi.

I have 2 Sony Car Audio head units both with faulty tuner modules. The
module is labelled TUX-020, and is listed online simply as "mounted
circuit board", it is also no longer available. I am able to get
schematics for the main unit, but this does not include any details of
the tuner block at all. I suspect Sony regarded it as a "black box".

One of the units tunes to AM stations fine, but FM reception is
extremely faint, barely audible behind the background noise. The tuning
voltage does sweep when I do a seek, and since the local stations are
faintly audible I suspect some failure in the front-end.

The second unit does not tune at all, though noise is present and
changes when an aerial is inserted. On this one the tuning voltage
remains high and does not sweep at all, obviously no reception on any band.

Car aerial has been confirmed good with a working unit. I have swapped
the tuner modules between the head units and the fault travels with the
module, confirming that the fault is with the module itself.

Does anyone have a schematic for this module? Failing that does anyone
have an old head unit with a good module (possibly one with a faulty CD
mechanism or output stage)? Or possibly some idea of where to start
fault finding? There are a lot of models from this vintage (around 1999)
which appear to use this module. If it's any help in identification, the
unit is a face-off with CD/MD changer control.

I would just buy a new head unit, but I have a 10 disc CD changer fitted
to the vehicle which is in good working order.