thought I'd step away from the arrandale thread for a while to ask something productive. My sister just had the logic board replaced on her 15" penryn mbp.. I believe it's the penryn model.. it has the 128mb ati graphics.. Long story short.. the computer was working perfectly until the logic board needed replacing under apple care. Ever since apple replaced the logic board, there has been a very soft buzzing sound coming from the bottom of the screen near the fans.. it happens when you start the computer from cold after sitting and also when you put very light pressure on the screen. or when you tilt the screen in certain positions you will hear the noise.. It's hard to describe the sound, it almost sounds electrical, like a circuit hissing type sounds or kinda like something is touching the fan while spinning.. But the service guy also replaced the fan and made sure nothing was touching it, so that was ruled out as the cause. No one at the apple store can figure out what is wrong.. it started doing this only after they replaced the logic board. The computer works fine but the noise is an annoyance and worries me about a problem down the road. Has anyone experienced this or know what might be causing it..