macbook fails to connect to unsecured wifi

Here's the background info, I think it has something to do with it. My brother gave me this Macbook as a hand me down. Here's the details:

Model Name: MacBook

Model Identifier: MacBook4,1

Processor Name: Intel Core 2 Duo

Processor Speed: 2.4 GHz

anyway, the problem is that I have an unsecured public wifi signal within range here at home and Icant get the macbook to connect to it, yet I can get my iphone to connect to it without any issues whatsoever, right next to the Macbook.

it doesnt ask for any passwords on my iphone either.

the signal DOES show up under airport but when I try to connect to it it always says connection timeout. ive been reading all over google and i'm getting nowhere!

if you have questions let me know.