Mac Mini Airport Sporadic Reception

Question

I've been dealing with the same issues for 2 months and 4 visits to the apple store. The problem is basically the same but slightly different than other posts on the same subject. I set up the Intel Mini in our room and once the high speed was hooked up to the house - fired up the base station extreme. I searched for the network and it refused to show up in the menu bar, however the Linksys from our neighbor across the street shows up quite well. I turned the airport off and back on several times until the base station shows up. I select the base station network and nothing happens. Not even an error dialogue. So I went back up to the Airport menu bar and the network disappears.
The base station is approximately 21' away in a wide open room configuration. I went to the next step and placed an airport express in the same room w/in 5' of the mini, set up to continue the base station network, and still nothing appears in the menu bar except the Linksys.
On the first visit to Apple they replaced the Airport Card. I took the mini home, same problem. I returned it to the store, I received a message that the computer works fine but I needed to bring in the base station for diagnostics.
I received a call this morning to tell me I could pick up both items, they are normal and working fine.
In the meantime, I've shared with the technicians that I have already reinstalled the software, updated any software or firmware for the mini and base station as well as repair any permissions and checked disk.
Also - I have a backup Mini PPC that I can use when the Intel is in the shop. I swapped units and the PPC mini works flawless. For the heck of it, I took my wife's MacBook into the same room, at the same location AND covered it with a cardboard box with a peep hole and still it picked up the signal with no fluctuation. Just for grins and giggles, I did the same thing with my Powerbook G4 with the same positive results.
Everything works except the Intel Mini. So I'm preparing myself to go pick up the Intel Mini, bring it home to try it again with the same results and ponder what the computer would look like as a planter because that's about what it is good for if it doesn't work.
Any ideas as to what my next step could be. As a last ditch effort, could I run an ethernet cable from my Airport Express to the mini and hopefully pick up an Ethernet signal.
Any thoughts or Ideas would be graciously accepted.

Answer 1

I saw your post describing this yesterday in one of the other airport threads, and have been pondering possible responses, given the nature of the problem you describe.
The first thing to say is possibly the least relevant:
I took my wife's MacBook into the same room, at the same location AND covered it with a cardboard box with a peep hole and still it picked up the signal with no fluctuation. Just for grins and giggles, I did the same thing with my Powerbook G4 with the same positive results.
Not sure what this experiment was to try and discover, but cardboard is not the sort of material that would have any real influence on wifi signal. At 2.4GHz, radio transmissions travel effectively through such materials as if they were not there. Indeed, it requires material far more dense, and generally more likely to reflect the signal (such as metallic ductwork) or absorb it (such as the human body).
Despite that, the test with MacBook and G4 laptop picking up the wifi signal is valid in the sense that it demonstrates a usable wifi signal in the same general location the mini appears not to work. That isn't to say, however, that the signal is strong enough to overcome the mini's relative lack of sensitivity, and because of that I would suggest you experiment a little further, this time using the software I mentioned in the other thread - AP Grapher. Install that on both mini and one of the laptops. Using the laptop where you know the network is detected, check the signal strength and quality. Next, with the mini in as close to the same location as the laptop was, run AP Grapher and see whether or not it registers the signal. Likely it will, but if the noise level is notably high, the system will not offer it since it's not usable. If that is the case, you may have sources of interference in the area to which the mini is more sensitive than the laptop. That interference may not be within the building, let alone the room, and certainly does not need to be in the line between base station and system, so moving the mini and base station around may give you some idea as to whether there are better locations for either or both.
If the wifi network doesn't show in AP Grapher at all, then you have an issue with the mini, either in MacOS where it is perhaps not running the correct kernel extensions, or, most likely, the physical hardware such as antenna itself, or the connection of antenna to card. The Apple store or service provider you took the systems to really can't test the viability of the system and base station for use in your location, only that they are working and connect on the bench - perhaps with little space between, and almost certainly without any of the same potential sources of interference.
Without knowing for sure how old your mini is, I would have to say that in this situation I'd be inclined to think that Apple should be asked to repair it under warranty if it is less than a year old, based not on their testing of it, but your complaint that it doesn't connect using Airport, when in reality it should. I would have to say however that while a range of 21 feet is not great, you would actually be better off, I suspect, hard wiring the system to your router and thus using ethernet. It's double the maximum theoretical speed of 802.11g wifi, and in practical terms if there is interference present, your wifi speed even when connected could we well below maximum theoretical level.