820-00165 cycling 100ma -20ma

[TBFix]

Had a bit of spillage around U5110, I replaced u5110 and surrounding component's. Board draws 100ma then drops back to 20ma. PP5V_S4RS3 is missing so is P5VS4RS3_EN (pulsing)

 

[2informaticos]

Post U5110 signals/voltages now.
Did you try SMC bypass?

 

[TBFix]

U5110
pin 1 = 3.42v
pin 3 = 3.42v
pin 4 = 2.81v
pin 5 = 3.4v
pin 6 = 3.4v
pin 7 = 3.4v
pin 8 = 3.4v

No response from SMC bypass.

I removed U8005 as it looked like small amount of spillage and unit draws 200ma and fan spins fast .
PP1V05_S0 is present but if u8005 is replaced it goes back to cycling.
Bad pch?

 

[2informaticos]

As all liquid damaged boards, I recommend to reball SMC.
Also check all SPI Bus Series Termination resistors and their traces.

 

[TBFix]

I reballed Smc, then replaced it and all spi termniation resistors and lines to the bios chip are good. Seems when PP1V05_S0SW_PCH_HSIO is connected via U8005 then it starts cycling.

 

[2informaticos]

Did you try known good BIOS?

 

[TBFix]

Yes, still same

 

[2informaticos]

Remove U8130 and check if something change.

 

[TBFix]

Just getting back to this now. I removed U8130 and it jumps to over 200ma then back to 189 with fan running full speed.

 

[2informaticos]

Did you resolder U8005?

 

[TBFix]

After resolder U8500 then it drops back to 20ma. I noticed U3900 was getting hot so removed it but still the same. I got PCH_HSIO_PWR_EN then 1.05v on
PP1V05_S0SW_PCH_HSIO on u8500 but then it dropped back to .30ma.

 

[2informaticos]

Looks like CPU issue...

 

[TBFix]

When I remove U8500 it stays at 120mv and
ppbus_g3h is at 8.12v.

U1950
SYS_PWROK_R = 3.3v
CPUVR_PGOOD_R = 3.3v
ALL_SYS_PWRGD = 3.3v
PM_S0_PGOOD = 3.3v
SMC_DELAYED_PWRGD 3.3v
PP3V42_G3H = 3.4v

 

[2informaticos]

"ppbus_g3h is at 8.12v"
Change SMC, probably last chance...