One of our Macs is a late '09 iMac. It received a new HDD and panel late last year as a result of the recall so we decided to keep it. It is running fine except for a noise that occurs during start-up. The noise sounds mechanical and is not a noise that I associate with a hard drive. The noise is coming from the general area of the optical drive and only lasts for a couple of seconds during start-up. Is there an utility that I can use to test the optical drive? Or, does anyone have other thoughts? Thanks in advance. FWIW - I did search but did not find an appropriate thread on this subject. My apologies if this was already covered. I am not one who thinks that the forum's search capacity is "robust".