820-3115 no wifi, Io0r error

jgraffis

New member
working on this liquid damaged 820-3115, after u.c. the board powered on but had no wifi, and left shift key not working, also io0r sensor reading above hight point.

i got the shift key issue taken care of by replacing the keyboard connector.

Io0R current sensor is reading 10.999 a -I did check the u5410 area all looks good
pin3 3.31v
pin4 12.55v
pin5 12.48v
pin6 3.31v

not sure if this would be a smc issue or something else.

Then no wifi has me mixed up also
After changing wifi card and cable, checking for crap inside the connector i noticed i wasn't getting voltage out of q3550 so i changed it after checking the resistors and caps, but still no voltage out and no short to ground. not sure if the Io0R problem is causing the no wifi issue. would it be possible to run 3.3v from one side of q3550 to the other to check if that still works temporarily?

any help would be great thanks.
 

dukefawks

Administrator
IO0R error is probably bad traces from R5410 to U5410.

Why are you changing parts? Did you even measure PM_WLAN_EN_L and AP_PWR_EN ?
 

jgraffis

New member
i will check traces and report back. this is the first time I've had a board with no wifi and it not be the card/cable/connector issue, hence why i chose to start by replacing the card and cable. i will check for pm_wlan_en_L and ap_pwr_en. also.
 

jgraffis

New member
i do have 3.3v on PM_WLAN_EN_L, Ive got 0.135v on AP_PWR_EN. i checked and no short to ground on this line. it looks like PW_PWR_EN comes from XDP_DB2_PCH_GPIO10_AP_PWR_EN which is the same 0.135v. would this be an issue with the u1800?
 

dukefawks

Administrator
u5410 pin5 is 2.4kohm pin4 0.0kohm also.would seem pin5 has a bad trace?
No idea what you are doing here. Is it that difficult to measure 2 traces between R5410/U5410?

Is R2067, R2596 good? Resistance to GND on AP_PWR_EN?
 
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