Wifi-issue "No Hardware detected", but Bluetooth okay!
I've read many postings in many threads about MacBook Airport/Bluetooth-Card ("No wifi-hardware installed") issues...
Also some suggestions about fixing this problems at component level.
But most of them end up in successful SMC or PRAM-Reset. Some are working at component level on the LogicBoard, but 99% of the problems are solved in changing the inductor L3404 or some in changing L3401.
But back to my special problem:
I've got problems with a combo-card (Airport/Bluetooth) in a white MacBook 13" 7.1 (Mid 2010).
A friend gave me two of these older MacBooks. One is functioning good, the second one doesn't have WiFi (while Bluetooth is okay).
At first I resetted PRAM and SMC but nothing changed.
The system goes on to say, there isn't WiFi-hardware attached...
In the system-profiler under "Network->WLAN" isn't a WiFi-card present, only the driver and WLAN-software is shown:
The next step was to change the combo-cards between the both MacBooks.
The good system was able to see other's combo-card without problems, the bad system still doesn't "see" the airport-section of the combo-card (bluetooth was going on to functioning correctly – on the first and the second card).
So it was evident, that something isn't okay with the mainboard.
I found many dialogs to this problem – so the thread in the the macrumor-forum too:
There "Dadioh" discusses with "russthechamp" about this problem.
Now I took a few measurements on my two LogicBoards (LBs) and found out, that the described inductors "L3401" and "L3404" are good. But I wondered that the voltages around the MOSFET "Q3450" were different on both LBs. I hope you could help me. I'd be very, very grateful to you, if you'd do so?
Here is the relevant part of the schematics with my voltage-values:
What do you think about that?
Is it a defective MOSFET?
Btw: over R3450 I measure on the good LB something around 32kOhm, on the defective Board something around 13kOhm. Nominal this R has 100kOhm.
Sorry for my poor english...
I am looking forward and hope to hear from anyone who works at component level on this issue.
Best Regards from Germany! Georg