故障现象: 三无(灯亮)
机芯: UL21飞利浦单片
机型: 2513UI,AT25135,AT25215Z,AT2516G,AT2516UG,AT25286,
AT2527,AT25181,AT25166(I),AT2565,AT2565A,AT2565(F),
AT2570UB(I),AT25189B,AT25276,AT25166,AT25206,
AT25276G,AT2565(I),AT25286(F),AT25166G,AT2560B,
AT2590B,AT2590UB,AT25166U,AT25106B,AT25215ZU,AT2575B,
AT2570UB,AT25211A,AT25166I,NT25A11,NT25A21,NT25A51,
AT29189B,AT29106B,AT25289B,AT34189B,AT34281,AT34187,
AT34276,AT34276(F),AT34286,AT34286(I),NT34181B,
AT34U186,2926UI,AT29266,2927U,2927U(I),AT2975,AT29166,
AT29128,AT29286,AT29187,AT29166UG,AT2916UG(F),
AT29166(I),AT29286(I),AT29166G(F),AT29286(F),
AT2960B,AT2916UG,AT25266,AT29215Z,AT29229,AT29329,
AT29386,2526UI,AT29211A,AT2988U,AT2990U
检修过程: 检修:开机测TDA9373的1脚(STDBY)始终是高电平,将1脚短路强行 开机,有高压起振的声音,说明CPU工作不正常没有输出正常的开机指令。开机测TDA9373供电脚54.56.61三脚3.3V供电正常,测晶振两端电 压2.2V正常,当测TDA9373的2脚3脚时(SCL、SDA)发现3脚电压明显偏低,说明总线控制不正常,将数据线外接各芯片的对应管脚断开,当断 开NJW1136的14脚(SDA)时,9373的3脚电压恢复正常,说明NJW1136损坏,试换之开机一切正常
故障板名称: 主板
故障元件位号: IC601
处理措施: 更换
图片: 无
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