captainmac
Member
Am struggling a little today with this board and need some clearheaded suggestions; had a couple in a row and can't think straight
Board might have had some work done on it, but i think i spotted all the mistakes (some coils of PMIC were taken off, but so far i don't know why, nothing else seemed missing.)
all USBC ports draw 5V steady and seem to have all their LDOs out of the port controllers.
PPBus was cycling quickly from 0 to 12.3V, along with PP3V3_G3H_RTC constantly trying to come up with some voltage (too quick to read)
I first removed R9707: Enable for U6903 was cycling as well, so i took it off and then PPBUS Stabilizes to 12.3V
I then thought my U6903 was bad (also because it looked to be cycling up to 2.7V and not to 3.3V, which is odd), diode-mode on C6912 was reading just a little low as well so i replaced U6903 (for the second time), and put back R9707:
Now output at C6912 is again cycling from 0 - 2.7V, as well as PPBUS cycling again.
i took off R6934/35 to see if there was a difference, and when these fuses are off, i get steady 3.3V at C6912.
I then thought, there must be a short after R6934/35 on PP3v3_G3H_RTC, but i cant find it, diode mode is OK at around .380
any idea what is causing this, or am i missing some steps?
Thanks in advance!
Board might have had some work done on it, but i think i spotted all the mistakes (some coils of PMIC were taken off, but so far i don't know why, nothing else seemed missing.)
all USBC ports draw 5V steady and seem to have all their LDOs out of the port controllers.
PPBus was cycling quickly from 0 to 12.3V, along with PP3V3_G3H_RTC constantly trying to come up with some voltage (too quick to read)
I first removed R9707: Enable for U6903 was cycling as well, so i took it off and then PPBUS Stabilizes to 12.3V
I then thought my U6903 was bad (also because it looked to be cycling up to 2.7V and not to 3.3V, which is odd), diode-mode on C6912 was reading just a little low as well so i replaced U6903 (for the second time), and put back R9707:
Now output at C6912 is again cycling from 0 - 2.7V, as well as PPBUS cycling again.
i took off R6934/35 to see if there was a difference, and when these fuses are off, i get steady 3.3V at C6912.
I then thought, there must be a short after R6934/35 on PP3v3_G3H_RTC, but i cant find it, diode mode is OK at around .380
any idea what is causing this, or am i missing some steps?
Thanks in advance!
Last edited:
