There isn't a practical way for the components of the logic board to
be upgraded, so the best most cost-effective path would be to get
a later model MacBook or MacBook Pro with higher specifications.
The internal wi-fi connection may have been damaged, if a hard
disk drive were upgraded or replaced; so the take-apart to chase
down source of the issue - may include small cable replacements.
A connector may have been jarred loose over time.
iFixit shows parts for several portable Mac models:
https://www.ifixit.com/Store/Mac
A helpful iFixit repair guide can be found on their site. This one shows
several different processor models, with a similar take-apart path:
• MacBook Core2Duo - iFixit guide:
https://www.ifixit.com/Device/MacBook_Core_2_Duo
Due to slight differences in the build model & year specification, a
few models covered in the above guide have additional information
on other pages in iFixit site. ~ I've looked around & note this factor.
These portables are much more accessible than older iBook G4/G3.
You may be able to find USB wi-fi 'external dongle' or plug-in antenna
that could work with the MacBook 13-inch Late 2007 you have.
So this may be a more cost effective path to attempt to access wi-fi.
Also businesses that restore • Macbook • Macbook Pro (repair centers)
such as wegenermedia, powerbookmedic and others who restore Macs
may have few different models in stock, & they can be cost effective...
If looking to be able to run a much later system be sure to see information
at everymac.com for the minimal specs require to run later OS X versions.
In any event...
Good luck & happy computing! 🙂
