The machine adopts CXA2549M, AT6392H and CXD3008Q as servo. Using ES410SF, ES3883F to extract the integrated board. First check the ES3883F chip peripheral components, there is no exception. Due to ES3883F chip set video coding, video digital to analog conversion, audio digital to analog conversion, karaoke reverb, PLL clock and output terminals of the auxiliary functions in one, to have a higher chance of failure, the estimates may be ES3883F caused by poor "Bu Bu" sound, and more for ES3883F, but the replacement fault phenomenon remains the same. And then boot carefully examined and found in the play in the process of press the pause button, "Bu Bu" sound disappeared; switchs on the mobile phone without disc has no "Bu Bu" sound. The analysis did not appear when playing "pitapat" sound and audio and video decompression on chip. The decompression in the decompression process is: DSP processing chip CXD3008Q sent out of the digital data information is added to the ES4108F internal pre processing, get the image data and audio data, and sent to a random buffer memory of the image data storage area or the audio storage area for a temporary storage, then in under the control of the CPU, the input buffer data decompression operation of sound or image processing. From the above analysis, the ES4108F decompression chip or random buffer memory D1616AB-B bad will cause the "Bu Bu" sound soft fault. ES4108F chip pin more, and more difficult to remove the welding, while the random buffer memory pin less, easy to remove and welding. So he decided to hand the existing D4516161BG5 substitution D1616AB-B, after substitution sound normal, "Bu Bu" sound disappeared, fault completely ruled out.mZDservice manual download site