A1707 Speakers issue

[Mineccia15]

Hello, I have an 820-00281 board with strage audio issue.

The right speaker came I for replacement because of randomly loosing the tweet tones. Replaced with new one and is better but still sounds distorted.

I replaced U6550 and is almost perfect but still has same distortion.

Now after 1 minute of playing music both the speakers looses the tweet. What can it be?

 

[2informaticos]

U6450 and U6500 are the tweeter amplifiers.
Check C6450 and C6500.

Headphones sound is correct?

 

[Mineccia15]

Headphones sound is correct? yes
C6450 and C6500 i repleced just in case, no differences.

replaced u6500 no differences. still audio goes lower after 20-30 seconds on both the speakers.

 

[2informaticos]

Are you sure only tweeters are affected?

 

[Mineccia15]

no at this point.
i am a bit lost. how can I check what is not working?

 

[2informaticos]

1000hz audio signal test - Google Search

Test with different frequencies...