I've been recording the audio output from my PSR3000. Whilst I've seen (and reported here) waveform clipping in the past due to excessive mix level in midi files I've now got a much stranger problem and I wonder if anyone else has seen this.

Basically, if you look at the audio waveform it is clearly not symmetrical. The +ve side of the waveform looks fine but the negative side looks compressed and low-pass filtered!

I get this on midi file, styles or live playing. I've used two different power supplies. I've changed the EQ. I've reset the keyboard. No change.

I'm capturing from the Phono sockets, I haven't bother capturing from the jack sockets are these are downstream from the phono so I'd expect the problem to be seen there as well.

It still sounds OK which may just confirm that my hearing is getting worse....

My only thought at present is take the lid off and waggle everything! Are there any
chips in sockets that might have crept a little?

To summarise: HELP!!!