故障现象：F30—ⅡD型200mAX线诊断仪，按下曝光开关枪手后有X线产生，但出现曝光不止．分析检修：根据故障现象，首先检查JDs继电器，发现该继电器在选定时间以后，触点不释放．放将检测重点放在限时电路板上。该机的报时电路基本原理是：利用电容器的充放电，来控制充气稳压 Symptoms: F30-IID 200mAX line diagnostic instrument, press the exposure switch gunner X-ray generated, but there is more than exposure. Analysis and maintenance: According to the fault phenomenon, first check the JDs relay, found that the relay is not released after the selected time. The test focuses on the time-limited circuit board. The basic principle of the timing circuit of the aircraft is: use of the charge and discharge of the capacitor to control the gas pressure regulator