MacBook Air 11″ fully functional except no Wi-Fi. Apple quoted $700 for replacing the whole logic board. Macbook model: A1466 Year: 2015 Logic Board number: 820-00164.
Diagnosis:
Remove the old Wi-Fi card, replace with our known good one. Boot into OS, and there is still no Wi-fi hardware found. It confirms that the fault is on the logic board.
Analysis:
The wi-fi card must co-operate with the logic board with these power rails and control signals:
logic board provides power rails pp3v3_s4 and pp3v3_wlan
logic board sends AP_RESET_CONN_L to initialize wi-fi card
wi-fi card responds with AP_CLKREQ_Q_L to the logic board requesting a system clock
logic board sends system clock PCIE_CLK100M_AP on request
wi-fi cards uses a pair of PCIe bus PCIE_AP_D2R and PCIE_AP_R2D to communicate with the logic baord
Repair:
Check power rail pp3v3_s4, 3.3 V, ok.
Check power rail pp3v3_wlan, missing. It comes from u3550 WLAN switch chip.
Check u3550 power supply pp3v3_s5, 3.3V, ok.
Check u3550 enable signal smc_wifi_pwr_en, present.
u3550 has been provided all the sufficient and necessary working conditions but still no output. So the u3550 chip must be not functional.
Replace u3550 and problem solved, easy fix.
Note: u3550 is the chip number on Apple logic board electronic circuit diagrams (schematic 820-00164).
The test of good customer service is when things go a bit wrong. There was some confusion about one aspect of my repair and Frances resolved the problem effortlessly and with a smile. You can place your trust in this organisation company. Excellent! They care about their reputation, which is a great thing.
Mokka Mil
8 months ago
It-Tech Online did a fabulous job on my MacBook Pro repair. Frances was very clear about how to fix the issues I had, how much it would cost and how long it would take. The repair was on budget, turned around within a couple of days as discussed and I have my computer improved and working better than before. I would recommend Frances and her team very highly.
ANDREW Gash
9 months ago
Absolutely fantastic experience. You'll be provided not only their professional repair service, but also free but still professional education on how to make the best of your devices and how to properly look after your gadgets. Will definitely be a loyal returning customer,
Steven Lee
1 year ago
I had a great experience getting my water damaged Macbook Air (2015) fixed here. I was able to mail my laptop to Frances to get it checked out and repaired. Once I sent it (from around Doreen area to her shop in Bentleigh East) it took less than a week for her to find out what was wrong, get the necessary parts and fully repair my laptop and then send it back to me. The correspondence was very friendly and professional and I am going to definitely recommend this service to anyone that needs it!
benji d
1 year ago
I had a GPU fault on my Macbook Pro which made it shut down at odd times and finally it would not boot at all. I was very sad. I spoke to Frances on the phone, she walked me through the repair process and the price, everything was very clearly communicated. I posted my Macbook Pro to Frances that day, she fixed it and now I am writing this review on my amazingly resurrected Macbook :-) Now I am very happy again.
Thank you Frances, you are amazing
Nick Buckmaster
1 year ago
What a great shop! Francis is amazing, her attitude and energy to help is excellent. Took two macbooks in for repairs and upgrades after being told by another shop to replace. Could not be happier, its been a few months and they have not skipped a beat.
This is easily the best experience I have ever had with a business, cannot fault it.
Thanks so much!