一台日本光电公司生产的三导心电图机ECG－53O3在开机使用时突然发现有故障，而前一天还在正常使用。其故障主要表现为导联不能切换，VI～V3各导均无信号。该机型是国内大中型医院比较常用的心电检查仪器。由于该机操作简单，性能优良，很受临床医疗科室的欢迎。该机本次故障点 A three-lead electrocardiograph ECG-53O3 produced by a Japanese photoelectric company suddenly found a malfunction when it was turned on, and it was still in normal use the previous day. The main manifestation of the failure is that the lead cannot switch, and there are no signals for each of the VI to V3 leads. This model is a commonly used ECG examination instrument in large and medium-sized hospitals in China. Due to its simple operation and excellent performance, this machine is very popular with clinical medical departments. The machine’s fault point