Blaupunkt Denver repost

[Mark]

I have a Blaupunkt Denver car Cd player, and have gotten closer to the
problem since my earlier post. It happens wether on the Cd or the
radio. It is sort of a cutting out of the audio, similar to a skip on
the cd. The problem is volume level dependent, when I crank it up it
happens, and when I turn it down it plays normally. Sometimes it will
be playing fine, and come to a loud area in the music and the problem
starts. Someone said it might be the amplifier IC's, so I have ordered
some of these, but could it be a capacitor problem as well? anything
else to check? I want to make sure I dont blow the new amp IC's.

Thanks

 

[Jim Adney]

I have a Blaupunkt Denver car Cd player, and have gotten closer to the
problem since my earlier post. It happens wether on the Cd or the
radio. It is sort of a cutting out of the audio, similar to a skip on
the cd. The problem is volume level dependent, when I crank it up it
happens, and when I turn it down it plays normally. Sometimes it will
be playing fine, and come to a loud area in the music and the problem
starts. Someone said it might be the amplifier IC's, so I have ordered
some of these, but could it be a capacitor problem as well? anything
else to check? I want to make sure I dont blow the new amp IC's.

Does it affect both sides together? If so look for problems in the
common areas. If not, look in the output areas.

Things to look for: Cold solder joints, broken speaker wires.

-

 

[Mark]

It affects both sides and when it happens there is a total absence of
music.
It has 2 amp IC's (TAD7375). Solder joints look good. Could it be both
IC's are bad? I am using a 4 speaker setup. Is intermittent high
volume clipping a possible failure mode of these IC's?
I have some replacement IC's that I havent installed yet. Just
wondering if I am going after the correct component.

Thanks much.

 

[Jim Adney]

It affects both sides and when it happens there is a total absence of
music.
It has 2 amp IC's (TAD7375). Solder joints look good. Could it be both
IC's are bad? I am using a 4 speaker setup. Is intermittent high
volume clipping a possible failure mode of these IC's?
I have some replacement IC's that I havent installed yet. Just
wondering if I am going after the correct component.

If it affects both channels simultaneously then this pretty much
clears anything in the separate channels from blame. You have to look
at parts which both channels share, like the power supply, power
switch, ground, etc.

-

 

[Mark]

Well It has 2 of these TDA7375 IC's, and the pinouts on each provide
for driving 4 speakers. So would the power go through one of these and
then the other? If so then it would seem that it could still be a bad
IC. Again the problem is a high volume cutout on all 4 speakers. Unit
plays fine at low volumes. If it was a power supplly or ground
problem, I would think the problem would happen at low volumes as
well.

Thanks for any input.

 

[Jim Adney]

Well It has 2 of these TDA7375 IC's, and the pinouts on each provide
for driving 4 speakers. So would the power go through one of these and
then the other? If so then it would seem that it could still be a bad
IC. Again the problem is a high volume cutout on all 4 speakers. Unit
plays fine at low volumes. If it was a power supplly or ground
problem, I would think the problem would happen at low volumes as
well.

Hmmm, any chance that the high volume playing is actually shaking a
loose connection somewhere? How about something getting hot and
protecting itself by shutting down temporarily?

I'd forget about the big ICs. They're not the problem.

-

 

[Bob Kos]

How bout a bad speaker?? Or incorrect polarity? If it's shutting off under
high volume, maybe you have some kind of load problem causing the IC to shut
down . Maybe as a safeguard, the design of the stereo dictates that both
are shut down.

You have the data sheet. Is this type of protection built in?

 

[Mark]

Another piece of the puzzle-- the IC's are getting very hot. Almost
too hot to touch. Could this be caused by a reversed polarity speaker
wire?

Thanks for any help to this problem.

 

[Jim Adney]

Another piece of the puzzle-- the IC's are getting very hot. Almost
too hot to touch. Could this be caused by a reversed polarity speaker
wire?

No

-

 

[Mark]

Ok I fixed it, either bad front speaker or bad wiring. When I fade to
the rear speakers it plays fine. I think it might be a speaker wire
grounding out to the frame of the landcrusier at the doorframe/ hinge
area.

Thanks for the leads.