Hello everyone!
I have this board that got slightly water damanged and it is stuck at S5 state. It pulses once every 5 seconds.
When connected the magsafe 2 to the bench psu, the current goes from 0.02A to 0.10A when is pulsing.
When using the genuine magsafe 2 charger, the light turn on and it became green and then amber. The fan is not spinning.
When I tried the SMC bypass mode, the fan spins a quarter every 5 seconds and the pulsing is still present every time the fan spin.
The pulses are present in the CPU Vcore rails on L7320 and L7310.
At a visual inspection I noted that:
U1950 had the c1950 burnt on pin #1 and it didn't have contact with the PP3V42_G3H line. I removed that cap and jumped a wire from the pin #8 of U1950 to the nearest spot where PP3V42_G3H line is present.
R5620 has a burn mark on pin #2 and C5620 is corroded. Some traces of corrosion are also present around U5620.
C7319 has a burn mark on pin #1, resistance to ground of PPBUS_S5_HS_COMPUTING_ISNS is over than 1M ohm and it rapidly decreases to Kohm range after few seconds
I took a look at the wiki page about the pulsing condition and I've checked U5110. Its looking good and all the resistors and capacitors read good values with no shorts, even when compared to a functioning board.
Also R1275 is measuring a good 0ohm value.
I took some measurements:
pp3v3_s5_avref_smc 3.3V
ppbus_g3h 8.6V
ppvrtc_g3h 3.3V
PCH_SRTCRST_L 3.33V
PCH_INTVRMEN 3.23V
PCH_DSWVRMEN 3.23V
SYSCLK_CLK32K_RTCX1 0.44V
PM_DSW_PWRGD 3.39V
PM_BATLOW_L 3.38V
PM_RSMRST_L 3.30V
SPIROM_USE_MLB 3.30V
pp5v_s5 5V
S5_PWRGD 3.3V
pp3v3_s5 3.3V
pp3v3_sus 3.3V
PP1V05_SUS 1.050V
PM_RSMRST_L 3.33V
PM_PWRBTN_L 3.39V
PM_SLP_S5_L pulsing
PM_SLP_S4_L pulsing
PP3v3_S4 240mV pulsing to 1.5V
RTC_RESET_L 3.33V
PLT_RESET_L pulsing
PM_S0_PGOOD pulsing
ALL_SYS_PWRGD pulsing
PM_PCH_SYS_PWROK pulsing
PM_SLP_SUS_L 3.33V
I took a video with the infrared camera and I noticed that U3900 get warm with the peak temperature of 27 celsius in a partcular spot when the lines are pulsing. Maybe it's nothing relevant but I was curious to know if it had something to do.
Any ideas of what else to check? Could be the SPI chip corrupted?
I have this board that got slightly water damanged and it is stuck at S5 state. It pulses once every 5 seconds.
When connected the magsafe 2 to the bench psu, the current goes from 0.02A to 0.10A when is pulsing.
When using the genuine magsafe 2 charger, the light turn on and it became green and then amber. The fan is not spinning.
When I tried the SMC bypass mode, the fan spins a quarter every 5 seconds and the pulsing is still present every time the fan spin.
The pulses are present in the CPU Vcore rails on L7320 and L7310.
At a visual inspection I noted that:
U1950 had the c1950 burnt on pin #1 and it didn't have contact with the PP3V42_G3H line. I removed that cap and jumped a wire from the pin #8 of U1950 to the nearest spot where PP3V42_G3H line is present.
R5620 has a burn mark on pin #2 and C5620 is corroded. Some traces of corrosion are also present around U5620.
C7319 has a burn mark on pin #1, resistance to ground of PPBUS_S5_HS_COMPUTING_ISNS is over than 1M ohm and it rapidly decreases to Kohm range after few seconds
I took a look at the wiki page about the pulsing condition and I've checked U5110. Its looking good and all the resistors and capacitors read good values with no shorts, even when compared to a functioning board.
Also R1275 is measuring a good 0ohm value.
I took some measurements:
pp3v3_s5_avref_smc 3.3V
ppbus_g3h 8.6V
ppvrtc_g3h 3.3V
PCH_SRTCRST_L 3.33V
PCH_INTVRMEN 3.23V
PCH_DSWVRMEN 3.23V
SYSCLK_CLK32K_RTCX1 0.44V
PM_DSW_PWRGD 3.39V
PM_BATLOW_L 3.38V
PM_RSMRST_L 3.30V
SPIROM_USE_MLB 3.30V
pp5v_s5 5V
S5_PWRGD 3.3V
pp3v3_s5 3.3V
pp3v3_sus 3.3V
PP1V05_SUS 1.050V
PM_RSMRST_L 3.33V
PM_PWRBTN_L 3.39V
PM_SLP_S5_L pulsing
PM_SLP_S4_L pulsing
PP3v3_S4 240mV pulsing to 1.5V
RTC_RESET_L 3.33V
PLT_RESET_L pulsing
PM_S0_PGOOD pulsing
ALL_SYS_PWRGD pulsing
PM_PCH_SYS_PWROK pulsing
PM_SLP_SUS_L 3.33V
I took a video with the infrared camera and I noticed that U3900 get warm with the peak temperature of 27 celsius in a partcular spot when the lines are pulsing. Maybe it's nothing relevant but I was curious to know if it had something to do.
Any ideas of what else to check? Could be the SPI chip corrupted?
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