各类监护除颤器设备电路复杂，维修相当困难。即使修好，要写出好的能被别人借鉴的检修文章同样困难。本例故障涉及７张图纸，为了技术交流，愿以此文形式尝试，望同行评述。一、故障现象：心电监护和非同步除颤正常，但不能进行同步除颤，同步除颤指示灯也不亮。二、原理说明 All types of guard defibrillator devices have complex circuits and are difficult to maintain. Even if it is repaired, it is equally difficult to write good repair articles that can be learned by others. The failure of this example involves 7 drawings. For technical exchange, it is willing to try in the form of this article and look for peer review. First, the failure phenomenon: ECG monitoring and asynchronous defibrillation is normal, but can not be synchronized defibrillation, synchronization defibrillation indicator is not bright. Second, the principle of explanation