This board had liquid damage, I saw red points and destroyed test points near one side of SMC, it looks like liquid spread out on all the board both sides but no heavy corrosion.
The board was spinning only once for 4-5 seconds and just stop. There was no usual RTC cycling (on/off, on/off and on).
All rails ppbus_g3h: 8,6V and pp3v42_g3h: 3,42V with orange/green light including PWROK 3.4V on pin 3 of U1950, VCORE 1.75V, 32Mhz, PPVRTC were present during the laps where fan spins. When fan stops there was no more pm_slp_s4_l and got only S5 and SUS rails.
What I did:
I replaced R7121 (120ohms instead of 10ohms), this changed nothing.
I checked near smc and repaired traces going to SMC from R5178 TDO and R5182 SMC_BIL_BUTTON (physically not used in this board). This changed nothing.
I checked for SMC_RESET_L, it was present 3.4V but when I touch the test point with my probe in voltage mode it made the fan spin again and stop, I noticed also the magsafe light switching to green and coming back to orange. I replaced just in case U5110 but this also changed nothing.
At this point I decided to give SMC a slight reflow and the board now boots ok
Now the issue:
Fan goes progressively high but it’s not trackpad TS0P related issue. I ran EFI and found the following errors:
1) Display Port (test 2 verifes no more than one error in 30s) -> Error – Lane count is zero
I will confirm tomorrow with internal lcd and run again EFI. I used only external monitor can this only be the cause?
2) VP0R -> Error – Sensor is reading below the low limit Error
This error appears only with battery plugged, I will confirm tomorrow and let it charge or just try another one. Hardware profile shows -6.5V
And I am using genuine but 85W charger, is that the reason? I would expect a higher value with this charger.
3) TM0P MLB Top -> Error – Sensor is reading below the low limit
Hardware profile shows -124Celsius must be a short or an open condition?? It says Memory proximity sensor. In schematic there is no reference to an MLB top sensor except for Q5850 marked “Placement note: TBD” (To be determined or what??).
My only guess is Q5850, because it’s on the TOP and near ram memory as reported by EFI.
U5810 looks a little shitty no way to tell if someone tried tor repair or only crap from liquid damage I will replace it anyways.
Any thoughts about these errors?
Thanks
The board was spinning only once for 4-5 seconds and just stop. There was no usual RTC cycling (on/off, on/off and on).
All rails ppbus_g3h: 8,6V and pp3v42_g3h: 3,42V with orange/green light including PWROK 3.4V on pin 3 of U1950, VCORE 1.75V, 32Mhz, PPVRTC were present during the laps where fan spins. When fan stops there was no more pm_slp_s4_l and got only S5 and SUS rails.
What I did:
I replaced R7121 (120ohms instead of 10ohms), this changed nothing.
I checked near smc and repaired traces going to SMC from R5178 TDO and R5182 SMC_BIL_BUTTON (physically not used in this board). This changed nothing.
I checked for SMC_RESET_L, it was present 3.4V but when I touch the test point with my probe in voltage mode it made the fan spin again and stop, I noticed also the magsafe light switching to green and coming back to orange. I replaced just in case U5110 but this also changed nothing.
At this point I decided to give SMC a slight reflow and the board now boots ok
Now the issue:
Fan goes progressively high but it’s not trackpad TS0P related issue. I ran EFI and found the following errors:
1) Display Port (test 2 verifes no more than one error in 30s) -> Error – Lane count is zero
I will confirm tomorrow with internal lcd and run again EFI. I used only external monitor can this only be the cause?
2) VP0R -> Error – Sensor is reading below the low limit Error
This error appears only with battery plugged, I will confirm tomorrow and let it charge or just try another one. Hardware profile shows -6.5V
And I am using genuine but 85W charger, is that the reason? I would expect a higher value with this charger.
3) TM0P MLB Top -> Error – Sensor is reading below the low limit
Hardware profile shows -124Celsius must be a short or an open condition?? It says Memory proximity sensor. In schematic there is no reference to an MLB top sensor except for Q5850 marked “Placement note: TBD” (To be determined or what??).
My only guess is Q5850, because it’s on the TOP and near ram memory as reported by EFI.
U5810 looks a little shitty no way to tell if someone tried tor repair or only crap from liquid damage I will replace it anyways.
Any thoughts about these errors?
Thanks