You don't need the optical drive to boot. So disconnect that from power and the noise will be gone.
Then fix whatever you broke. That can be the anything related to the CPU, the motherboard, the graphic card (if you have one) or some cables that are loose accidentally.
I recently replaced the thermal paste on my cpu and only messed with about 3-4 cords which I put where they were after. And I came across a problem when I turned on my computer, it turns on and has no display but also makes a noise from the optical drive (DVD drive) and just repeats the noise with no display. All of my fans and LEDs are on but no display. I've already replaced the cmos battery and released all the electricity after resetting it to give it a clean boot but it still persist the problem.