故障现象：血流图描笔基线不移，无规则漂移。故障分析与检修：首先将“封闭一观察一记录”控制开关置“封闭”位，将血流图描笔开关置于闭合状态，观察故障现象依旧，因此可推测故障可能在血流主放大电路。由于血流通道和心电通道的主放大器相同，所以可通过调换两块主放大板 Symptoms: The baseline of the blood flow chart is not shifted, and there is no regular drift. Failure analysis and maintenance: First, the “closed an observation record” control switch is set to “closed” position, the blood flow diagram pen switch is placed in a closed state, observe the fault phenomenon is still the same, so it can be speculated that the fault may be in the blood flow of the main amplifier circuit . Since the main amplifier of the blood flow channel and the cardiac channel is the same, the two main amplification plates can be exchanged.