HP Z2 Mini G3 Workstation repeatedly makes chime sound when in sleep mode

[TkmLinus]

HP Z2 Mini G3 Workstation is repeatedly making the chime sound as if a usb device is connected whenever it goes to sleep mode. This same issue is occuring on several of the same computer model at my school. I have discovered if I disconnect the usb cable that connects the pc to the monitor this noise stops. How can I fix this? Thanks in advance!

[DGroves]

if mail is setup, incoming mail can cause this, also you can try disabling the  USB wake on xxx options in the bios

[TkmLinus]

I will have to get the technology department to look into these fixes, unfortunately the BIOS settings are password protected. Mail is not set up on this pc. When it sleep mode it sounds as if someone is continuously plugging and unplugging a usb device(there are no pauses or gaps in the chimes)