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[例1] 故障现象 通电后各功能键均失效。 分析与检修 试机时发现,一接通电源,磁鼓便旋转,好象是结露保护,但检查保护电路并未动作。由此可初步判定系统控制电路失常,应先重点检查微处理器IC6001(MN67434VRSB)的工作状态。微处理器的正常工作取决于四个条件:(1)正常的工作电压;(2)正确的复位电压;(3)正确的品振信号;(4)正常的时钟/数据通路。测IC6001的(11)与(42)脚工作电压为5V,正常;测得(84)脚复位电压仅为1.8V的不稳定值,说明复位电压偏低(正常值为5V)。造成该电压太低的常见原因有:(1)复位电路有问题;(2)得位支路漏电;(3)IC6001内部损坏。断开(84)脚
[Example 1] Symptom After power failure of each function key. Analysis and maintenance test machine found that, once connected to the power, the drum will spin, as if the dew protection, but check the protection circuit does not move. It can be initially determined that the system control circuit malfunction, priority should be to check the microprocessor IC6001 (MN67434VRSB) working conditions. The normal operation of the microprocessor depends on four conditions: (1) the normal operating voltage; (2) the correct reset voltage; (3) the correct signal vibration signal; (4) normal clock / data path. Test IC6001’s (11) and (42) feet operating voltage of 5V, normal; measured (84) pin reset voltage is only 1.8V instability, indicating the reset voltage is low (normal value is 5V). Common causes of the voltage are too low: (1) reset circuit problems; (2) slip slip in the branch; (3) IC6001 internal damage. Disconnect (84) feet