MacBook won't take an IP

Hello there, MadGambla.

The following Knowledge Base article offers some great recommendations for troubleshooting Wi-Fi connectivity:

Wi-Fi: How to troubleshoot Wi-Fi connectivity

http://support.apple.com/kb/HT4628

Start with these steps:

First, determine what the issue is. Knowing what's wrong will help you identify appropriate troubleshooting steps.

1. Does the symptom occur with more than one Wi-Fi device?
   
   • Wi-Fi issues may be related to the network in question or they may be related to the Wi-Fi computer joining that network. Usually, if other computers or devices (such as the Apple TV or iPhone) are able to get on the Internet without issues, then your Wi-Fi router is probably fine.
   • If you only have one Wi-Fi device, proceed with this article.
2. Make sure your software is up-to-date.
   
   • Install all software updates available for your Mac.
   • If you use a third-party Wi-Fi router, check with the manufacturer to confirm that it has the latest firmware installed. If an update is available, follow the manufacturer's instructions for updating the firmware.
   • To determine if your Apple Wi-Fi base station firmware is up-to-date, see Updating your software.
3. Check your connections.
   

   Some networking issues may be caused by loose or disconnected cables. Verify that all Ethernet and power cables connected between your modem and your Wi-Fi router are correct. Checking that devices such as your router and modem are on, disconnecting and carefully reconnecting Ethernet cables, and/or replacing damaged Ethernet cables may resolve the issue without any further troubleshooting.

4. Verify that you are using the recommended settings for your device.

   See Recommended settings for Wi-Fi routers and access points.

5. Restart your network devices.

   Powering your modem or router off for a few seconds and then on again may resolve network issues without any additional troubleshooting. If you have phone service through your ISP, power cycling your modem may interrupt that service. You may need to contact your ISP in order to restore your phone service if your modem is reset or powered off. Ensure that you have alternative means to contact your ISP (such as a cell phone) to avoid unnecessary delays in restoring your Internet or phone service.

Thanks for reaching out to Apple Support Communities.

Cheers,

Pedro.

Hello again, MadGambla.

Awesome! Glad the information helped in resolving your issue.

Sincerely,

Pedro.