Thank you for using the Support Forum. Please take a look at the article Printer Resets or Turns Off Frequently from the online support for your printer. Also make sure that you are not trying to connect wireless with the Ethernet cable attached. You must select one or the other. Please see the article Ethernet Network Not Working to select one or the other. Please consider contacting your support centre for further assistance.
I have a new WC3335 (purchased 1m ago). The printer seems fine when turned on without being connected to a network, but when plugged into the LAN in the office building by ethernet, or when connected to network by WiFi, it keeps cycling on and off. Printer starts up normally, prints a text page, then after about 20s goes dead and re-starts, running through the same procedure. This happens continuously (it'll keep going all day) when the ethernet cable is plugged in or if it has WiFi log in credentials (the WiFi issue was especially difficult because there is barely enough time to log on as administrator and then reset the TCP/IP settings to kick it off WiFi......I almost resorted it to taking it somewhere out of the building to get it to stop!
IT support for the building (I'm in a building with multiple offices rented to individual businesses and a centralised IT network) say that there's nothing about the network that should be causing this behaviour.