Falcon sound problems (DSP)

[derkom]

The Faclon DAC does get quite warm under normal operation.

[kohli79]

The Faclon DAC does get quite warm under normal operation.

OK thanks! 👍

[Steve]

Yes and that is just for video, the DAC you'd be concerned with would be the Crystal DAC in the top right corner above the SDMA.

[kohli79]

I played again with the SDMATest program. The sound interference / crackling are always at 33Hz, 25Hz, 20Hz. Mostly at 33Hz. When I switch from 25Mhz to 32Mhz (master clock) everything is ok and no problems.

[Steve]

Since you are in Germany I think you may have a great choice of Falcon experts who may be able to look at it for you. Have you been speaking on atari-home.de? Perhaps @tuxie might know somebody

[kohli79]

Since you are in Germany I think you may have a great choice of Falcon experts who may be able to look at it for you. Have you been speaking on atari-home.de? Perhaps @tuxie might know somebody

No not yet, wanted to ask there again ... Thanks anyway.

[kohli79]

I tested the cold spray on the Falcon today.
I couldn't find anything on any IC, except on the SDMA.
As soon as I'm on with the spray, the crackling in the ACE Tracker is gone. In the DMA-DSP test, these spikes also disappeared for a short time, until it warmed up again.
So the SDMA chip seems to have a problem !?

Video link attached.

https://youtu.be/6Mr0kqsFWJE

[Steve]

Perhaps the chip needs resoldering, I doubt the chip itself would be faulty.

[kohli79]

Perhaps the chip needs resoldering, I doubt the chip itself would be faulty.

Yes, I will try again with re-soldering.
So not me but my specialist ... ;)

[kohli79]

My specialist looked at the Falcon yesterday and re-soldered the SDMA. Without success! :(
Still the same problems.
Unfortunately it doesn't have a reflow station to change it. I will ask in the German Atari forum.
I could get a replacement from best-electronics in the USA. According to their catalog, they have some in stock.