Share the voltage to ground of the following:
PP5V_S4
PP3V3_S5
PP5V_S4_P2V7NAND_LB
PP3V3_2V7_NAND_VCC ; measure @ L9400
PP5V_S4
PP3V3_S5
PP5V_S4_P2V7NAND_LB
PP3V3_2V7_NAND_VCC ; measure @ L9400
-
-
Measure voltage to ground (carefully) of P5VS4_EN @ U7650 which is used to enable PP5V_S4.Comment
-
Other other idea?Comment
-
Do you have the trackpad attached or disconnected? If it is attached, disconnect it and test again.Comment
-
Review the power rails for your board here:
Power Rail List - LogiWiki
Note all that are not present.Comment
-
All of these are missing.
PPVCC_S0_CPU
PPVCCSA_S0_CPU
PPVCCGT_S0_CPU
PPVCCIO_S0_CPU
PPVCCEDRAM_S0_CPU
PP0V6_S0_DDRVTT
PP0V6_S3_MEM_VREFDQ_A
PP0V6_S3_MEM_VREFCA_A
PP0V6_S3_MEM_VREFDQ_B
PP0V6_S3_MEM_VREFCA_A
PP1V8_S4
PP1V8_S3
PP1V8_S3_MEM
PP1V8_S0
PP1V0_S3
PP1V0_S0SW
PP5V_S4
PP5V_S4SW
PP5V_S4SW_ISNS
PP5V_S0
PP5V_S0_KBD
PP3V3_S4
PP3V3_TBT_X_S0
PP3V3_TBT_T_S0
PP3V3_S4_BT
PP3V3_S4_TPAD
PP3V3_S4SW_SNS
PP3V3_S4_MESA
PP3V3_2V7_NAND_VCC
PP3V3_S4_SOC_PMUComment
-
For each power rail that is not to the expected voltage range or is zero volts, measure their resistance to ground. A good idea to locate each inductor onboard and perform the same resistance measurement to ground. Report any off measurements which may be due to a shorted capacitor or something else. A low resistance will cause an excessive current draw and this will be sensed by the buck regulator or the current sense amplifier circuits and then will result in powering down that rail. Music stops playing, party is over, everyone has to go home.Comment
-
Check that SMC_RESET_L and SMC_USBC_INT_L are properly pulled up to 3v3.Comment
-
I can't believe it.
The Macbook came with an original USB-C charger, which was showing 5V when connected to my meter. So I used another original Apple charger I have. Same story.
Earlier today I found a Anker USB-C charger I have and I thought "why not?". I plugged in and... 5V... boom! 20V! And the board started.
Which means both original chargers are not ok. And I wasted my time and yours.
I'm really sorry about that.
The laptop was freezing and rebooting, but it was because of a swollen battery. I disconnected it and it's working fine for hours. Now I need to by a new charger (or not) and battery.
I'm really sorry about that.Comment
-
hello everyone, let me ask, I have a macbook which is stuck at 5v and 0.03 A when tested with a usb tester. Previously I wanted to replace the screen on the device, but by accident I forgot to unplug the battery. This caused the MacBook to get stuck at 5v, previously I had replaced the CD3215 (U3100) IC because it was warm. After I replaced it the problem was still not resolved. Please guide. Thank you -
Hi all,
I have an A1706 that was liquid damaged, the logic board turns on and works when the battery connector is not plugged in, but when the battery is plugged in, the computer is stuck on 5v @ 30-40 Mah, and USB-C meter will reboot every 5 sec or so, pressing and holding down the power button will make the USB-C meter to stop boot looping, and if you keep holding it, fan will quickly spin up and turn off.
when the battery is unplugged and plug in the charger then plug in the battery it will stay on 20V and 1.6A-2.6A but when you unplug the charger, the computer... -
Hi,
I have a MacBook Pro 13 inch A2238 M2 and it was stuck 5V with 0 amps. I measured some important lines and I found a short on PP3V8_AON_MPMU_ISNS_VIN, I tried injecting 1v and I saw heat coming from the mPMU so I removed the pmu thinking that was the problem. I don't know why I didn't check the other side of the border but there it was, a shorted cap. I replaced the cap and the short was gone, so I reballed the PMU and put it on again but voltage was still stuck at 5V and the current was fluctuating between 0 and 0.45 amps. I checked under the thermal camera and I saw the mPM...04-02-2025, 05:02 PM -
Dear friends,
a close friend of mine gave me this machine, she told me that the last days the fan was going high and that it was heating up too much for the usual things, and that suddenly one morning it didn't start anymore .
I opened it and inspected carefully with a high magnifying lens, found no oxydized spots but a short on PPBUS_G3H , then a blown U6903.
I changed U6903 with a new one, PPBUS_G3H became 558 (measuring with red probe to gnd , and black on F7000) , PP3V3_G3H_RTC 463.
Now when I plug the usbc cable (original Apple 61W power supply), nothing starts automatically,... -
Hey guys,
I got a MacBook Pro a1989 820-00850-A dead for repair. The MacBook itself was off for a month or so and it didn't power on. I tested using ammeter and it was stuck on 5v. Opened the machine and found a short on ppbus_g3h, corrosion near the right spkr_amp. removed the spkr_amp and saw short on ppbus_g3h. plugged in to power, boosted to 20v .600A and then back down to .300A. Trackpad was clicking when on .600A but no image etc.
Later, I tried again but it dropped down to 5v and never boosted back to 20V. checked board again and found ppbus_g3h shorted again....10-06-2025, 08:45 AM
Comment