820-3208 - no fan spin

[2informaticos]

Mentioned signals appear much later...
PCH should first release SLP_SUS and next SLP_Sx, after got PWRBTN reaction from SMC.

"with L7260 removed there is 2.6+v at both pads"
What???
The coil is a part (important) of buck controller!!!
Any voltage measure without coil is a non-sense...

Change U7201 and Q7260; pay atention to R/C7264.

 

[jpadie]

Yes - it's very odd. the voltage stays the same whether the coil is there or not. makes me very suspicious of U7201. but .... there is no enable inputer on U7201 either

 

[2informaticos]

Post basic voltages for U7201 and U7941.

 

[jpadie]

U7201

mostly at or close to 0mv except for
3 80mv
10 20mv
16 800mv
17 2.7v
18 2.7
22 3.3v
23 8.2v
24 2.7v
25 2.7v
26 2.47v

U7941
1 3.42v
2 0
3 0
4 3.39v
5 0
6 2.7v
7 0
8 0

 

[2informaticos]

As expected, missing SMC_PM_G2_EN. It comes from SMC.
You didn't mention incorrect PPBUS_G3H before...

Check SMC_RESET_L value.
Also try a reflow to SMC.

 

[jpadie]

why do you think that PPBUS is incorrect? It is 8.2v.

SMC_RESET_L is high (as per message yesterday).

yes. missing SMC_PM_G2_EN as per the same previous message.

 

[2informaticos]

PPBUS_G3H correct value is aprox 8.4-8.5V.
8.2V means SMC don't talk with ISL6259!
And this be caused by SMC, or ISL6259, or something else connected on SMBattery Bus.
As you also miss SMC_PM_G2_EN, SMC is first suspect here.
The best option is change it. But I recommend to reball it first.

 

[jpadie]

ah. that is interesting. PPBus has always been 8.2v even when the board was in an S0 state. definitely something fishy.

i will reflow the SMC later. I don't have any stencils here to do a proper reball of a donor.

 

[2informaticos]

I did many at hand; there are aprox 150 balls, not too many...
0.35-0.4mm for commodity, but you can also use 0.3, even 0.45mm.

 

[jpadie]

ha. it is a plan ... but i am rather middle aged and have shaky hands!

i may try with some old donor boards one weekend!

 

[jpadie]

reflowing the SMC did not work by the way. I will debug a bit more later.

 

[2informaticos]

Don't be afraid, I'm also middle age and work with one eye only...