3 beeps in a loop mean the processor is not recognizing the memory.
I would need to gather your processor model and Brand name and model of your RAM memories. We need to know if they are fully compatible.
I would recommend to downgrade the BIOS to version 70. Please use F7 method.
Instructions for F7 BIOS Flash update
Intel i5-3570k; Kingston KHX16C9B1R2K/8X