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故障现象:铃声小、失真。解决方法:拆开U900屏蔽罩,找到R900、R901、C902、C904,放首mp3歌曲;先测C902两端波形,应光滑且幅度正常。两端幅度差别大,则C902损坏;无波形请查软件及U900。再测R900与R901相连的点的波形,幅度应很小,若没有则R900开路;若很大(相当于C902波形的幅度)
Symptoms: small ringtones, distortion. Solution: open the U900 shield, find R900, R901, C902, C904, put the first mp3 songs; first test C902 both ends of the waveform should be smooth and normal amplitude. Large difference between the two ends, then the C902 damage; no waveform please check the software and U900. R900 and then measured R901 connected to the point of the waveform, the amplitude should be small, if not, then R900 open; if large (equivalent to the amplitude of the C902 waveform)