820-3476-A with dead IO board (no usb, no wifi), replaced IO board but wifi still not working

[protocold]

So the IO board was completely dead with no usb whatsoever, after replacing it, the USB is back but wifi still not working, wifi card tested good on another computer.

where should I look?

 

[2informaticos]

Check L9501 and C9532/33.

Bluetooth works?
Did you try another RIO flex?

 

[protocold]

Tried another RIO flex, same.
Bluetooth works.

L9501 is ok. Continuity is ok and diode mode to ground reading is 227.

C9532/33, no short across.

 

[protocold]

did i check this right?

 

[2informaticos]

Checked continuity from C9532/33 and L9501 to J9510?
Also check continuity between MLB and RIO boards, for airport lines (flex connected, of course).
Compare diode mode readings on airport related lines with good board.

 

[protocold]

Continuity from C9532/33 and L9501 to J9510 are OK.

Diode mode reading of:
PCIE_AP_D2R_N = 330
PCIE_AP_D2R_P = 330
PCIE_CLK100M_AP_CONN_P = 240
PCIE_CLK100M_AP_CONN_N = 240
PCIE_AP_R2D_N = open (diode mode reading kept at 1)
PCIE_AP_R2D_P = open (diode mode reading kept at 1)

is this normal? I dont have another good board to compare.

 

[2informaticos]

Check on the other side of the caps.
Is normal to get OL on the connector side, once no airport card is connected.
Don't forget the lines from pins 22 & 24 of J9510.

 

[protocold]

pin 22 & 24 of J9510 diode mode to ground reading is 427
After connected airport card, PCIE_AP_R2D_N & P both have values.

 

[2informaticos]

Did you check diode mode on the other side of C9532/33?
I forgot to mention pins 52 and 54.

Once RIO board is connected (airport card inserted), check voltages at pins 22, 24, 52, 64 (J9510).

 

[protocold]

sorry for a stupid question.. i have the board out of the case(but with RIO board connected), how do I start the board? (magsafe is orange and mouse no led)

 

[2informaticos]

All iCore Macbook boards start automatically when charger is plugged in; if no battery connected.
You can also use R5115/16 pads, instead of power button.

 

[protocold]

All iCore Macbook boards start automatically when charger is plugged in; if no battery connected.

^^ I dont have battery plugged in, but how come the usb mouse has no led if it automatically start?

 

[protocold]

i got it to start by putting it back onto the case just to make sure i didnt accidentally fry it or something.. it starts..

Now when I measure voltage on the RIO:

AP_CLKREQ_L is 0v
PM_WLAN_EN is 3.3v
WIFI_EVENT_L on the RIO board and it is giving 3.1v.. is this abnormal?

 

[2informaticos]

You don't get USB activity on RIO board?
The USB port from MLB also not working?

No idea about WIFI_EVENT_L; compare with working board.

"You can also use R5115/16 pads, instead of power button."
You don't need to put the board back on the shell to start.

BTW, machine automatically starts if you connect proper charger; Magsafe 2 original 60/85W in this case.