I'd say about every 15 minutes or so, a faint beeping noise is coming from my computer. It's really hard to tell where it's coming from, but I'm pretty sure it's my computer. I shut down my computer last night and I believe I heard it in the middle of the night. So I'm thinking it's my power supply. Do they sometimes beep to let you know they're about to go out? On the side of it it says LSP Ultra 550W ATX power supply, if that helps. Thanks.