Your Dell Printer Offline notice may have a number of causes, including outdated computer software, a problem with the printer's hardware connection to the PC (including cables or Wi-Fi gear), outdated printer firmware, or outdated PC printer driver software. In addition, any one of the following three factors could be the root of this problem:
To conserve electricity, the computer is turning off the wireless adapter.
The communication fault is being caused by the firewall or antivirus software.
Incorrect i.p address or missing network information in the printer settings.