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Hi guys, I got this 12 inch 2017 macbook with a totally destroyed BIOS chip... so I cannot read it and therefor cant flash it in a new chip..
I found some .bin files for this motherboard on the internet but unfortunately they are not working...
Any help will be much appreciated
Yea, just what I thought.. just wanted to make sure I wasn't missing something with that 5V_G3S line.
Unfortunately the client couldn't wait more.. so this one went out as No Fix..
Thank you very much anyways !
With the battery and charger connected, the cycles continue in the U3100/200 side it goes 20, 18, 0, 5, 8, 20 V and so on...
in the other side (UB300/400) goes :
UB400 0V (not shorted) I do have 3.3_LDO and X2 1.8_LDO but still missing 1.1_LDO
Could it be that I had a very bad luck...
yes, reading was using only the charger.
Right now, after the changes and using only the charger as well, I have in PPBUS_G3H 12.29 steady in both ports ( UB300/400 ) but in the other two, where 1V1_LDO shows up (U3100/200) is not steady. It goes to 12.30 and then goes to 6.34 , 10.40 and then...
Hola 2informaticos !
Confirmed, I have checked 1V1_LDO only in the powered port.
Resistors and traces are ok
UPC_TA_UART_TX & UPC_TA_UART_RX have 3.35 V (both ports UB300/400)
I found a little diference in diode mode readings in PP5V_S4_T_USBC 0.148 compared to PP5V_S4_X_USBC 0.203
Hi Piernov !
Thank you very much for this info.
I have replaced UB090 and i got back PP1V1_LDO in the master UB300 however PP1V1_LDO is still missing in UB400. So.. I have replaced UB400 again but still the same, no 1V1_LDO.. (no shorts around )
what do you think?
I'm working on a MB that came with a partial short an corrosion on CB300 and CB308 and had also a burned L8504.
Once CB300 & 308 were replace, PP3V3_G3H_RTC & PP3V3_UPC_TA_LDO came back but PP1V1_LDO is missing in UB300 & UB400 (PP1V8_LDO X2 are present)
Both CD chips (UB300/400) have...
yes, i have all LDOs present, 3.3 1.8 (X2) and 1.1 ( on each port where power is connected)
What could be the reason for 20V in DCIN when battery and charger connected but 5V with only the charger connected?
yeap, all USB-C ports have the same behavior. 20V with battery and charger only 5V just charger.
no shorts found, all diode mode readings are ok in LDOs.
CC1/2 pins. ? what is it?
anything else to check before the T2 firmware ?
I got this mac with a little water damage in the QB631 area and RB641 & RB631 were replaced.
I have 20v in DCIN only with the battery connected but it does not turn on. without the battery DCIN has 5V and all LDOs are present.
checking without battery i have:
PPBUS_G3H 12.28 V...