１台心电图机 ,说明书和资料均已丢失 ,故障现象为不能记录心电波形 ,其余一切正常。拔下热笔插头 ,测其电阻为无穷大 ,说明热笔已开路。换上热笔重新开机 ,还是不能显示 ,拔下热笔插头 ,量热笔插座两端电压为６Ｖ ,但一插上热笔 ,带负载再量热笔两端电压 ,此时几乎降为０Ｖ , For an electrocardiograph, the manual and data have been lost. The failure phenomenon is that the ECG waveform cannot be recorded. Everything else is normal. Unplug the hot pen and measure its resistance to infinity, indicating that the hot pen is open. Replace the hot pen and restart, or still can not be displayed, unplug the hot pen plug, the voltage between the two ends of the measuring pen is 6V, but once the hot pen is inserted, the voltage at both ends of the pen is loaded and the voltage is almost reduced to 0V. ,