820-3462 wifi disabled, keyboard partially working

[Bouba148]

Hi Team,

I have a 820-3462 with trace of liquid damage. cleaned with the Ultrasonic cleaner
I already fixed the backlight.
I had fans running at full speed: issue coming from the camera, now i've disconnected it and fans runing normally (all temp sensor reports normal temperatures)

Now i'm facing to 2 weird behaviors:
Regarding the keyboard: only few keys are working, the Trackpad works correctly.
Taken Actions:
Replaced the keyboard, and it's the same, with the same keys working. the Alt key is ok ( i can select the booting hdd)


Regarding the wifi:
when in the OS, it scans (wifi logo in action) but can't detect any network, when i click on network preferences, there it reports that the wifi state is disabled, when i click on enable it stays disabled.
Also if i go in the assistant wisard, there it can detect the surounding networks but can't register to any of them.
Hardware detected, Mac Adress OK
It can resgister to a network previously connected to.( same OS session with another macbook pro).
Beside that the thunderbolt brigde is connected.....how is this possible?
Could it be a kind of blacklisted motherboard? don't think so as I also replaced Airport card

Taken action:
Replaced Airport card with original RIO board: NOK
Replaced RIO board with original Airport card: NOK
Replaced Both together: NOK

I've mesured the differents voltages related to the Airport (AP) and WLAN, they seems all OK

External USB devices (flash drive, keyboard) : OK, I'll have to test the HDMI port.

Question:
Could both issues have a link? if yes i would redirect myself to U2700 (USB HUB Internal Devices ) and its surrounding area.
Could both issues + the camera have a link? that would redirect me plus to the U1800......

Maybe a communication signal is missing. Could it be related to the OS? as i'm testing it from installed Sierra USB 2.0 Flash drive (unfortunately i don't have an ssd for this board)
If you want me to take a specific mesurement feel free to ask.
I will also try from an OS installed on USB 3.0 hdd, and also will try the bluetooth asap and update.

 

[Bouba148]

Edit: I've attached 2 ASD test pictures.
Best regards

 

[dukefawks]

Measure diode mode on all keyboard connector pins.

Did you try a known good RIO flat cable?

 

[Bouba148]

Hi Dukefawks, thanks for your reply
here are the mesurements in diode mode with the red probe on the ground

With the machine OFF magesafe not plugged and the keyboard NOT connected

1: 0.448v
2: 0.448v
3: 0.449v
4: 0.321v
5: 1.098v
6: 0.705v
7: 0.703v
8: 0.704v
9: 0.702v
10: 0.703v
11: 0.696v
12: 0,700v
13: 0,701v
14:0,768v
15:0,702v
16:0,702v
17:0,701v
18:0,702v
19:0,701v
20:0,702v
21: 0,701v
22: 0,702v
23: 0,702v
24: 0,702v
25: 0,703v
26: 0,702v
27: 0,703v
28: 0,702v
29: 0,00v (normal it's ground)
30: 0.368v

with the machine ON with the DVM in DC Voltage mode :

4: PP3V42_G3H 3,410V
30: PP3V3_S4: 3,350V


With the keyboard connected:

1,2,3 turn to 3,39V when shift,ctrl,cmd key are pressed
4,5: always 3,4V
13: 0v

When the machine is ON with OS on usb2.0 flash drive:
Cap key led doesn't turn ON when pressed
6,7,8: 0V
9,10,11,12,14-24: 3,34V
25,26,27,28: 0V

When the machine is ON with no booting device (question mark)
Cap key led turns ON to green when pressed
6,7,8: 1,12V
9,10,11,12,14 to 24: 3,22V
25,26,27,28: 3,28V

30: always 3,35V

Just to let you know: i've ordered the ssd+flex ribbon+caddy to test it in "normal" conditions and not from OS installed on USB2.0 flash drive

Regarding the RIO flex cable , I have no guarantee that the one I tried is 100% Good.

Best Regards

 

[dukefawks]

Diode readings look fine so the connector may be suspect. Inspect the pins carefully, was there any liquid in the connector?

 

[Bouba148]

Hi Dukefawks, team,

Here are the last news:

Regarding the wifi:
now it works fine just after installing the OS on an interal ssd instead of running the OS from usb 2.0

For The keyboard:
I replaced the connector and now it's working much more better, i explain: all the keys works fine except those on the Vertical line of "9" "O" "L"...
Does any one knows where i can find the keyboard "matrix map" to know which WSKDB signal (pin) correspond to which line/letters on the keyboard

Best Regards

 

[Bouba148]

Update:
I've checked for no cut track from J5713 all pins properly connected where they're supposed to be.
Maybe bad "new" connector

 

[dukefawks]

Again, check diode mode on all pins of the keyboard connector and compare to previous measurement. Is it a known good keyboard?

 

[Bouba148]

Hi Dukefawks, I've ested all pins in diode mode and i have the exact same reading like previously which seems to be ok.
I've also tried another keyboard which is doing the exact same symptoms ("9" "O" "L"... not working) , that'swhy i've ordered another keyboard connector.
So i'll update you asap.

Thanks

 

[Bouba148]

Hi Dukefawks
Here is the Last update regarding that board:
I changed the keyboard connector and with the original keyboard(liquid damaged) many Keys doesn't work but the POWER bouton is OK.
With 2 others keyboards (1new the other used) :
ALL the Keys are working except the POWER bouton.

I'm out of idea, i will ask for another New keyboard to be sure.
Do you have any clue ?

 

[dukefawks]

If you are not sure if you have a known good keyboard then there is no sense in fixing a board that does not have an issue. Any retina/Air KBD is compatible for testing if you have anything lying around.