Atari STF - audio issues pops and crackles

[coonsgm]

I picked up an awesome STF that runs perfectly with the exception of occasional pops and crackles when no audio is being generated (no active sound or music). So when playing games and the like, there is no noticeable difference between this computer and any other ST I have.

The computer passes all diagnostic cartridge tests, runs gembench flawlessly (except for some pops and crackles)....no issues with any crashing of bombs.

PSU has been recapped (also tested with an adapated Meanwell PSU with same popping and crackling).

The Exxos "required" mods besides PSU have not yet been done....but based on reading about them they don't seem to address this type of issue...I am planning on doing them in the next week or so.

Any thoughts?

[exxos]

Maybe faulty YM chip or audio amp ?

[coonsgm]

I'll check them out.

[coonsgm]

I found the culprit. It was a capacitor in the audio circuit that had a dry solder joint...

Hey at least I had a project for a few hours....there is a wonderful satisfaction from finding an issue and fixing it. Even if it is such a simple fix.

[exxos]

[Badwolf]

BW