Free and difficult(ish)
Run a Wireshark trace while the machine is in sleep mode and find the originating issue.
If you have a contract with Xerox
Report it to 2nd level and get the Network log collected from the Device and Engineering may be able to find the issue for you
Free and can't really hurt to try
I unchecked those boxes, but wasnt worked and I disabled SNMP, but It worked weird. Sometimes fan ran sometimes stoped. How can I find what aplication or process is doing it?
Uncheck the 2 boxes below, if your PC is spamming the printer with SNMP requests, it may never get all the way to sleep, and even if it does, there is no reason the fan should not run at times, but if your PC is the cause, you need to figure out the source on it. Maybe just disable SNMP on the driver and check the boxes again if diabling them does stop the fans.
I bought new workstation and fan running in Sleep mode a when I turn off one of my PCs, it stops. Can you help me?