故障现象：治疗床不能升、降，可左右移动，平面可转１８０°，机架不能旋转，小机头也不能转。故障分析、处理：检查控制盒到机房的电缆、确定传输无误。检查手控盒、各开关接线完好、无脱落。查手控盒系统电路图纸，如图１所示，实测ＤＣ、ＤＥ间无电压，ｎｍ、１ｍ间无电压 Symptoms: The treatment bed cannot be raised or lowered. It can be moved left and right. The plane can be rotated 180°. The frame cannot be rotated. The small head cannot be turned. Failure analysis, processing: Check the control box to the computer room’s cable, confirm the transmission is correct. Check the manual control box, the wiring of each switch is in good condition and there is no shedding. Check the circuit diagram of the manual control box system, as shown in Figure 1. There is no voltage between the measured DC and DE, and there is no voltage between nm and 1m.