smiba
New member
[SOLVED][820-3115] PPBUS_G3H trolling me, System not going further then S5 & voltage drops
Customer came in with this laptop which suppositiously have been peed on "a little" (Eww!!!!), the customer already cleaned the motherboard them selfs with pure alcohol in a hope to fix it them selfs but no luck.
The motherboard itself looks alright, it has some heavily green(?) corroded parts. But most parts are untouched or looking almost like new, the only few corroded parts are related to thunderbolt. I even tried to replace some of the really corroded parts but obviously that didn't fix anything.
When powering the system on PPBUS_G3H drops from 13.3V quickly to ~3.4V and then slowly starts dropping until it hits 1.6-1.9V and goes back to 13.3V. At this moment trying to press the power button (or shorting the power_on test point) will drop the voltage again to less then 3.4V. This is exactly the same result you'd get by disconnecting the charger.
All the S5 power lines are up, it does not have any S3 power lines and if I remember correctly only 1 of the two S4 power lines.
The system has no fan spin (and obviously no chime). The charger has a green light, but only when you connected it before PPBUS_G3H started dropping, if this happened you'd need to wait 10-30 seconds before you can connect it with a green light. Connecting the power on a cold start it will always give a green light
My guess is that the charger's protection circuit is working and disables the power output because something is shorting. I have no idea what though, I've tested some of the major power lines and there is no short to ground.
Any idea where to look?
These were the power lines by the way in a state where the voltage on PPBUS_G3H isn't dropping:
PPBUS_G3H: 13.3v
PPBUS_S5_HS_COMPUTING_ISNS: 13.3v
PPBUS_S5_HS_OTHER_ISNS: 13.3v
PP3V42_G3H: 3.48v
PPVRTC_G3H 3.31v
PP5V_S5: 4.97v
PP5V_SUS: 0v
PP5V_S3: 0v
PP3V3_S5: 3.31v
Customer came in with this laptop which suppositiously have been peed on "a little" (Eww!!!!), the customer already cleaned the motherboard them selfs with pure alcohol in a hope to fix it them selfs but no luck.
The motherboard itself looks alright, it has some heavily green(?) corroded parts. But most parts are untouched or looking almost like new, the only few corroded parts are related to thunderbolt. I even tried to replace some of the really corroded parts but obviously that didn't fix anything.
When powering the system on PPBUS_G3H drops from 13.3V quickly to ~3.4V and then slowly starts dropping until it hits 1.6-1.9V and goes back to 13.3V. At this moment trying to press the power button (or shorting the power_on test point) will drop the voltage again to less then 3.4V. This is exactly the same result you'd get by disconnecting the charger.
All the S5 power lines are up, it does not have any S3 power lines and if I remember correctly only 1 of the two S4 power lines.
The system has no fan spin (and obviously no chime). The charger has a green light, but only when you connected it before PPBUS_G3H started dropping, if this happened you'd need to wait 10-30 seconds before you can connect it with a green light. Connecting the power on a cold start it will always give a green light
My guess is that the charger's protection circuit is working and disables the power output because something is shorting. I have no idea what though, I've tested some of the major power lines and there is no short to ground.
Any idea where to look?
These were the power lines by the way in a state where the voltage on PPBUS_G3H isn't dropping:
PPBUS_G3H: 13.3v
PPBUS_S5_HS_COMPUTING_ISNS: 13.3v
PPBUS_S5_HS_OTHER_ISNS: 13.3v
PP3V42_G3H: 3.48v
PPVRTC_G3H 3.31v
PP5V_S5: 4.97v
PP5V_SUS: 0v
PP5V_S3: 0v
PP3V3_S5: 3.31v
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