STANDBY時會有SI-SI聲, POWERON就無事, it's likey the oscillation noise induced by the (power) transformer 。(or 可能mounting screw鬆掉了??) remark: "POWERON就無事" ? --- what do u mean ?
u mean the SR6007 can be power on without problem ?
or, u mean no more the si-si聲 after the POWERON ? No way to DIY, unless it's just a case of mounting screw 鬆掉了. Either 入廠 to replace the transformer, or let it be.
STANDBY時會有si-si細細聲,另一極大原因係standby section既 (switching?) 火牛發震 (i.e. harmonic noise of the switching frequency)所致。師兄可以細心檢查它的機械結構有冇鬆 (e.g.浸漬不良。)。if it's the root cause, 換之可也。DIY冇計了。