L6653+L6599中PFC间隙振荡

正在调试LCD电源,200W.
现在是整板工作正常,效率也算可以,可就是PFC工作不正常,有轻轻的叫声.工作波形也不怎么正常.搞了两天了,还是没有解决...附上图,请DX们帮忙解决..
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