求助:我的SG1525的电路,一开如的是稳定的,后来降了

电路是这个样子,一开始输出是正常的,可是输出刚到5V时,SG1525就突然关断了,而且.输再降下来时它也不能现开启这是为什么呢?劳烦各位指教,路过的帮顶个贴,谢谢了!
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