Apple performa 630 series Servicehandbuch

 

 Troubleshooting

Symptom Charts/Audio - 4

 

Crackling noise is 

present when you 

play sounds other 

than system beeps 

and you are not in 

“play through” mode

1 If static noise varies when you adjust volume by Sound 

control panel, use Audio Volume Extension 1.1 or later. Note: 

Audio Volume Extension is available from standard Apple 

software update sites.

2 Replace logic board.

Sound distortion with 

MPEG board installed

Replace MPEG board with modified MPEG board. A modified board 

should have a jumper present from U5 Pin 2 to D1 Pin 1.