When troubleshooting a WLAN, a process of elimination is recommended.

In the figure, a wireless client is not connecting to the WLAN. If there is no connectivity, check the following:

If the PC is operational but the wireless connection is performing poorly, check the following:

Next, ensure that all the devices are actually in place. Consider a possible physical security issue. Is there power to all devices and are they powered on?

Finally, inspect links between cabled devices looking for bad connectors or damaged or missing cables. If the physical plant is in place, verify the wired LAN by pinging devices, including the AP. If connectivity still fails at this point, perhaps something is wrong with the AP or its configuration.

When the user PC is eliminated as the source of the problem, and the physical status of devices is confirmed, begin investigating the performance of the AP. Check the power status of the AP.