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The high pitch noise is the faulty color wheel. Part of the color wheel may be broken or the components that drive the color wheel such as the DMD board may be bad as well.
Here is a picture of the color wheel for reference CLICK HERE
That moves me to remember that you may have not had the lamp plugged in all the way. I had this happen to me before...I reseated the lamp and never happened again. Mitsubishi replacement housing don't always fit properly...I sometimes have to put my new bulb in the original housing for it to work. However the noise is related to color wheel problems.
I believe you are referring here to the cooling fan.