820-4924 liqued damage 18volt on pp3v42

[Repairable]

Hi all,

so got this puppy in from a repair shop they seem to have cleaned it.
wel around U7090 there was some water.
after replacing the ic and caps around it that had damage,
nice stable pp3v42

but nothing for the rest.
no pm_slp_s4_l
no vcore
no S4 lines
psirom looks good

could the 18volt on pp3v42 killed the board?

 

[dukefawks]

Green/orange light present?

 

[Repairable]

Yes starts green turns orange
ppbus-g3h 12,60v
smc-lid 3,3volt (memory not at shop atm)
smc-reset-l present 3,3v
SMC_ONOFF_L 3.3v

 

[dukefawks]

Check the usual, U6100 termination resistors/traces. Clock chip area, 3V to RTC. If there really was 18V on 3V42 the SMC would be dead, but it seems fine.

 

[Repairable]

u6100 ternimation resistors measure good and traces look good also the coper points are pretty and nice round

PCH_CLK32K_RTCX1 32.68mhz on osciliscope but jumping up and down from 32.86mhz to 32.89mhz (0.395volt i dont know if this is even needed please tell me if it is i think the mhz is the needed)

PPVRTC_G3h 3.392volt

spi_rom

pp3v3_sus 3.327v
SPI_MLB_IO0_MOSI 3.327v
SPI_MLB_IO1_MISO 3.327v
SPI MLBROM CS L 3.327v
SPI_MLB_IO2_WP_L 3.327v
SPI_MLB_IO3_HOLD_L 3.327v

 

[Repairable]

and 10 characters ofcourse

 

[dukefawks]

Check for power cycling on 5V rails. Check all rails for shorts.

 

[Repairable]

PP5V_S5 diode0.441 15.04kohm 5.02volt stable 2 spots measured

PP5V_S4 diode0.547 9.29 mohm 0 volt no spike when pluged in

PP5V_S3 diode0.401 14.01kohm

PP5V_S0 diode0.401 14.07kohm

 

[Repairable]

p5vs4_en diode0.539 102.8kohm 0.000volt

u8060
pin 1 + 3 5,02 volt
pin 2 0.000volt
pin 6+7 0.000volt

P5VS4_EN_D 0.000volt

s4_pwr_en diode 0.426 73.1kohm 0.000volt

S4_PWR_EN comes from PM_SLP_S5_L if i read back correct

PM_SLP_S5_L diode0.426 73.6kohm 0.000volt

 

[dukefawks]

SMC_ADAPTER_EN high? Batlow signal?

 

[Repairable]

SMC_ADAPTER_EN 3.392v
PM_BATLOW_L 0.035v
R1410 9.77kohm

 

[larossmann]

PM_BATLOW_L shouldn't be 0.035v.

 

[dukefawks]

I bet this will power on just fine with a good battery installed. What is PPBUS voltage on just the battery? Is it even charging?

 

[Repairable]

yes it does Duke, turns on with known good battery.

it also charges, booted to os and checked went up from 70% to 100% no issues.

charger connected ppbus_g3h 12.85V
only battery ppbus_g3h 12.57v



wont turn on with only charger ppbus_g3h 12.59v

 

[Repairable]

Normaal behaivoir?
the not booting with only charger that is....

 

[Repairable]

oke, this is fun.

when I insert a SSD (know working)
it boots fine, fan spins no issues charges etc.

when I insert the original SSD.
it wont boot unless I press the power button, the SSD is not recognized.
no fan spin.

not working SSD
when I then measure
PCIE_CLK100M_SSD_P 0.245 diode
PCIE_CLK100M_SSD_N 0.245 diode

Working SSD
when I measure
PCIE_CLK100M_SSD_P 0.030 diode
PCIE_CLK100M_SSD_N 0.030 diode

this is the only difference I could find.

hints are welkom

 

[dukefawks]

Hint: that SSD is dead.