exlaimation mark in wifi icon

When you see an exclamation point in the Wi-Fi menu, from the menu bar, select

 ▹ System Preferences... ▹ Network

Click the Assist me button and select Assistant. Follow the prompts. You may get a warning that Wi-Fi is not available, that you're too far from the base station, or that you're using the wrong password.

Assuming that you've ruled out those possibilities, restart the computer and try again. If there's no change, click the lock icon in the lower left corner of the preference pane and authenticate, if necessary. From the Location menu at the top of the window, select Edit Locations. A sheet will drop down. Click the plus-sign button to create a new location. Give it any name you want. In the new location, set up the Wi-Fi service with the same settings you used before. Click Applyand test.

If there's still no connection, and if you have control of the router, compare its settings to Apple's recommendations. Some third-party routers may be incompatible in 802.11b/g/n radio mode. Try setting the mode to 802.11n only.

This worked for me. Thanks

Power off the router. Unplug it from the wall. Wait for few minutes.

Power off the router. Wait a while.

Connect the router back to to the wall.

Power the router back on. Wait until all lights are lit properly.It will take a while.

Restart the computer.

Start up in Safe Mode.

http://support.apple.com/kb/HT1455

This exclamation mark in the Airport icon means that WiFi is working but the internet connection is lost.

You have to power off the modem, and the router, both ⚠. Then power up the modem and let it start up completely, then start up the router and let it start up completely, sometimes you also have to turn Airport off on the computer then on again when both modem and router are completely started up.

Hello Linc, I need your help in this thread

https://discussions.apple.com/thread/5733295?answerId=24477943022#24477943022&ac_cid=tw123456#24477943

please have a look,

Lex