What is happening to my MacBook Air?

Hi,

Got a MBA mid 2009 - 2,13 GHz C2D, SSD 128, Lion.

For the first 1,5 year of usage - mainly office stuff - I've been experiencing only overheating problems - fans at 6200 RPM, kernel_task 150%, etc. But some day strange things began to happen.

It started with sound. System began crashing 2-3 times a day - kernel panic and nice request to hard reboot, mostly during wake-up. After one such case, there was no sound any more - speaker icon grayed out and that's it. Occasionally after hard reset sound was on for some time, but scenario was the same - kernel panics. When the sound was on, I could see the error like:

17.04.2012 21:57:51,000 kernel: Sound assertion "0 != err" failed in IOHDACodecDevice at line 161 goto Exit
17.04.2012 21:59:03,000 kernel: Sound assertion "0 != result" failed in AppleHDANode at line 307 goto Exit

Anyway, most of the time the sound was off, system run stable - as I do office stuff on my computer I did not care - thought of some hardware issue related with sound card. Unfortunately, it become worse. Yesterday I woke up the computer without Wi-Fi. AirPort icon is grayed out, and "no hardware installed" message appeared.

I've done everything - PRAM reset, SMC reset, diagnostic tool run from the CD (no troubles found), scanned computer by AV software - NOTHING. Sometimes I got only sound, sometimes Wi-fi as well, but what is the strangest - when I manage to get the Wi-Fi operational (last time it started to work after switching on Bluetooth mouse) I got "read-only" lock on my excel sheet . Once I managed to have sound and w-fi up, but after closing lid and opening it, wi-fi stopped to work and the error appeared:

17.04.2012 19:32:38,000 kernel: no card!

As you can see, the system behaves totally awkward. It does not resemble hardware issue to me, as usually it is rather 0/1 behavior - either work or not, but what the **** is the relation between wi-fi card and filesystem?

Any ideas, clues, hints, whatever, that could help me out?

Kal

It sounds like you have a failing hardware issue. You can certainly try to reinstall the system, but I highly doubt it will fix the issue. Do you have Applecare? I'd recommend taking it to the Apple Store to have them look at it.

I dont really know much about taking apart a macbook air and I would imagine there are a lot of differences. I just built a 15" macbook pro and with various broken components it did a lot of interesting things. I am not sure where the wifi or airport card is on the air, on the macbook pro I know its in the black plastic piece that houses the hinges. There is a connector that goes from the logic board into that area and then fron the card to the antennas that run around the LCD.

If its not under Apple care and you are feeling brave here is what I would suggest,

From what I saw when I took mine apart the logic board to wifi connector was held in by some plastic piece(a softer plastic) a possibility here is that the plastic isnt holding the connector in properly. without that plastic piece the cable pulls out and moves pretty much completely effortlessly. that is one thing you could check.

the sound issue, Im really not too familiar with at all so I cant offer much.,

I build and sell PCs for a living pretty much and what this somewhat sounds like is a motherboard/logic board on its last leg. When I have has desktops come in before with bad sound and I add a sound card its usually just a matter of time until something else on the motherboard dies.

I would try an OS reinstall and if that doesnt work Im not too sure what else to recommend.

Well,

I can see, that wi-fi and sound module are separate from logic board and can be both replaced, but how can I determine, that those modules crashed, not the logic board?

Is it possible that something is wrong with the main board?

Kal

The only place I found that sold the wifi (airport) cards was some chinese company on ebay, I think they were about $35 and shipped for free. I tried sending them offers for $30 and $31 but they did not accept so I am assuming they are pretty firm on their price.

Im not too sure how you would test the components without another macbook air to try them on and see what happens. It is also very possible that the mainboard is failing. perhaps pull out/unhook both the sound chip and wifi chip and see if it gives you any troubles. Maybe if it works fine without the components hooked up you could attempt a replacement. The wifi card for $35 isnt a very expensive gamble in my opinion though youll have to find out which airport card yours usues if it is like the macbook pros setup (im not too sure).

the only reason I keep swinging back to mainboard failure in my head is that it randomly works then doesnt work. was the connector fine on the wifi card?

My colleague has 100% identical MBA model.

I swapped both sound and wi-fi module and the result is that on his computer both wi-fi and sound works and on mine don't.

Is is 100% evidence of broken logic board or there are other options?

I think the last chance is to install totally fresh SL system and check what happens....

Kal

probably would be a logic board failure in my opinion.

Id say attempt the OS re-install and cross your fingers. good luck.

just performed SMC and PRAM reset and sound started to work...

I believe wi-fi is somehow related with OS....

Kal

lol, well thats a great start. I seem to remember when I have built up macbooks in the past there were issued wifi related that caused me to re-install the OS.