Note: Restore images are available at http://service.info.apple.com. Select "Disc Images."
o ijj O NJ
Connector to Batteries & Charger
Study the block diagram to understand which I/O ports have a direct connection to the outside world and which ports have an I/O interface controller between the system I/O mapper and the outside world.
For example, let us say you are troubleshooting an AirPort connectivity symptom. Input to the AirPort Extreme Card comes from the MLB. Power and addressing of the card are necessary for it's operation. Microwave data output signal to the antenna is the desired output and this too is necessary for the card's operation. You have three components to check to discover fault with AirPort operation: MLB, AirPort Extreme Card, and antenna.
If installing a known-good AirPort Extreme Card restores operation, you need to focus on the original card. If the known-good card does not restore operation, you need to focus on the MLB or the original antenna.
When you focus on the MLB, from the block diagram, you can see that the MacBook (13-inch) AirPort Extreme Card is on the PCI Express bus. Investigate other devices on the PCI Express bus, such as the Ethernet controller. Determine if the Ethernet port is working. (System Profiler is a good tool to verify I/O.)
If the Ethernet port is working, the MLB is probably functioning; focus on the original AirPort antenna. As an additional test, if you can see both the known-good AirPort Extreme Card and original AirPort Extreme Card in System Profiler, suspect the antenna.
Was this article helpful?