3115, ambient air temp sensor error

[Alan.L]

the board was liquid damaged, corrosion was on the SMC and u5410 area.

it didn't turn on initially, after reflow then replaced SMC from a donor then now the board power up except fan goes high.

ASD reports Ambient Air temp error, memory temp errors and a bunch of other temp errors.
ASD hardware monitor reports, these sensors reading is -124. which means these sensors is not working,


Power to U5511 is ok

pull up resistors R5260-R5261 = 3.4v on both side

diode mode on pin9-10 of U5511 is 0.511

r5512, r5511, r5510 is in spec.
r5511 pin1 gets 3.3v, pin2 is pulsing from 3.269-3.29v

I've already replaced u5511, q5520, and SMC




have i used a bad SMC from a donor board?

 

[2informaticos]

Do you get correct AVREF_SMC voltage?
First replace trackpad board/flex with known good working.
Check traces from U5511 to Q5510/15/20.
Also test disconnecting J3502.

 

[Alan.L]

AVREF_SMC - 3.29v

trackpad/ js3502, yep, did these before.


U5511 to Q5510/15/20. traces all good.

 

[2informaticos]

Try other SMC.
Check traces from SMC to U5511, before replace it (once pulled out).

 

[Alan.L]

wow, what are the fecking chances!!!

SDA ball wasn't solder due to flux turned solid and blocking the pad.

I've cleaned, applied new flux and placed the SMC back in and reflowed into place without reballing.


now is working

 

[2informaticos]

"flux turned solid and blocking the pad"
Do you use chinese honey flux???
This shouldn't happen with Inventec/Amtech...

 

[Alan.L]

nope, amtech 599 real stuff. no idea how it happens.

could also be burnt edge bonding that i didn't clean probably.