Getting hung up on whether the LED works or not is a waste of time and energy in my opinion, this is why there is the airport icon in the task bar, it acts as the LED and places it in a place that is far easier to observe than looking at the back of the computer to see if you have a connection.
Baring this, there are several issues that prevent a wireless adapter from functioning properly or being recognized.
One is the PCI classification, if it's 0200 then the airport software wont be able to properly manage the card, the other is the Product and Vendor ID's are always a problem because this is how a card is recognized by the apple driver.
Because you have a bcm4318 from one OEM manufacturer, it may use a different classification and ID's in another OEM manufacturers card but the cards are identical right down to the markings on the PCB.
If you locate and install the PCITools found in XLabs you can isolate the exact ID's of the installed card by issuing "lspci -nnv" and it will also provide you with the all ID's including the subsystem ID's.
Information of importance:
CODE
04:02.0 Network controller [0280]: Broadcom Corporation BCM4318 [AirForce One 54g] 802.11g Wireless LAN Controller [14e4:4318] (rev 02)
This can be translated to: (see Proposed Method for better solution)
CODE
<string>pci14e4,4318</string>
Very few Broadcom cards are recognized as real apple AirPort Extreme cards just by adding the ID to the Info.plist, actually I haven't come across one yet that does yet people make this claim and I have tested the cards they claim to be using and they have not reported as such.
If you have access to a ubuntu installation you can rebrand the b/g and a/b/g cards provided you know what to change them too and they work flawlessly after that.
I have done this with Dynex, D-Link, HP, NetGear and LinkSYS cards with good success.
For 11a/b/g laptop miniPCI cards (not miniPCIe) I exclusively use the Dell DW1470 (BCM4309KFB) and rebrand accordingly (less than $20.00 on fleabay), once rebranded you no longer have to edit any files, the card works flawlessly and is supported natively.
You can even purchase a PCI to miniPCI adapter and use the card in a desktop computer that has an empty PCI slot and enjoy the benefit of supported wireless.
For 11a/b/g laptop miniPCIe cards (not miniPCI)you can use the Dell DW1490.
What I don't understand is why you have to add a million ID's to get them working?
I would have thought that the people thinking of these modifications and patches would know how to match the device based on it's classification and would remove the need to patch for each and every card out there.
I would think that the following "Proposed Method" substitution is a far better and more intelligent solution.
Current Method:
CODE
<key>Broadcom 802.11 PCI</key>
<dict>
<key>APRoamTrigger</key>
<integer>-91</integer>
<key>CFBundleIdentifier</key>
<string>com.apple.driver.AirPortBrcm43xx</string>
<key>IOClass</key>
<string>AirPort_Brcm43xx</string>
<key>IOMatchCategory</key>
<string>IODefaultMatchCategory</string>
<key>IONameMatch</key>
<array>
<string>pci106b,4e</string>
<string>pci14e4,4311</string>
<string>pci14e4,4312</string>
<string>pci14e4,4313</string>
<string>pci14e4,4318</string>
<string>pci14e4,4319</string>
<string>pci14e4,431a</string>
<string>pci14e4,4320</string>
<string>pci14e4,4324</string>
<string>pci14e4,4325</string>
<string>pci14e4,4328</string>
<string>pci14e4,4329</string>
<string>pci14e4,432a</string>
<string>pci14e4,432b</string>
<string>pci14e4,432c</string>
<string>pci14e4,432d</string>
</array>
<key>IOProviderClass</key>
<string>IOPCIDevice</string>
</dict>
Proposed Method:
CODE
<key>Broadcom 802.11 PCI</key>
<dict>
<key>APRoamTrigger</key>
<integer>-91</integer>
<key>CFBundleIdentifier</key>
<string>com.apple.driver.AirPortBrcm43xx</string>
<key>IOClass</key>
<string>AirPort_Brcm43xx</string>
<key>IOMatchCategory</key>
<string>IODefaultMatchCategory</string>
<key>IOPCIClassMatch</key>
<string>0x02800000&0xffff0000</string>
<key>IOPCIMatch</key>
<string>0x430014e4&0xff00ffff</string>
<key>IOProviderClass</key>
<string>IOPCIDevice</string>
</dict>
Explanation:- examine all cards that are assigned 0280 which are alternate network controllers (not ethernet).
- match all Broadcom ID's of these alternate network cards.
This would make all Broadcom wireless cards be recognized out of the box and wouldn't interfere with Broadcom Ethernet adapters reducing the amount of work required by the end user to get the card recognized.
Now, there is the odd OEM that has classified their cards as 0200, this should be changed to 0280, it will not affect the performance or use of the card, it will allow it to be properly recognized and allow it to be managed by the airport software which is another issue preventing some people from using their cards.