Philips HTS3450 - high pitched humming noise until warmed up

I heard some people talk about capacitors on the philips system because my surround system was emitting a high pitched noise a little after you turn it on. Several people mentioned this high pitched noise. It's almost as if when you let it warm up for 15 or 20 or more minutes it works fine. I was wondering if the 470uF capacitors were in the receiver or the amplifier in the subwoofer enclosure. And I wanted to know if everyone else had the same problem but cured it once the circuit board got warm.

Thanks,
Jeremy