Hi Dear Friends., Working on a MacBook Pro A2289 820-01978 stuck on 20V. Not taking any amps. Sometime it just jumps to .01 amp & that's it. PPDCIN_G3H (20V), FUSE F7000 (12V) & 3.3V & 5V are perfect on the motherboard & even the battery charges very well & this is the only time I see the amps start to increase charging the battery. Where should I start???? I do not see the power or power rail sequence in the schematics, is there any matching board to start my troubleshooting. Your help will be greatly appreciate. Thanks in advance
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Last edited by mferna14; 10-11-2024, 03:56 PM. -
I tried in DFU mode. My laptop with Configrator 2 surely sensed that there was a laptop in Recovery mode & without pressing any keys, the DFU box on the screen appeared. I try to Revive first, gave errors. Then tried an update, gave errors & tried many option where were present in the DFU Screen. & then last I tried to Recover & format, still gave errors. I think something is wrong with the main logic board, have to trouble shooting where the problem lies. Thanks mon2, if any tips pls. inform me.Comment
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Check the ssd voltage rails. If not present, test the resistance to ground of the same rails.Comment
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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,... -
Hi guys
I have a MacBook Pro A1990 that takes 4.9 Volts and .592 to .615 amps on one port. The other port on the left side power cycles with about the same amount of volts an amps but quickly power cycles. The same thing happens on the other side but opposite. So on the left side the bottom port stays on and on the right side it's the top one. I think it is a CD3215 chip but I am not sure how to test it or where to get one. I have checked for voltage at ppbus_g3h and it has 12.6 V which is also on fuses f7000 and f7001 I checked pp1v2_s3 and it has 1.2 V then... -
Hello everyone.
I have a problem finding the problem. MacBook came with a damaged flex usb c, 3 pins were shorted. No water damage.
Voltages I have:
pp3v3 g3h rtc
pp1v5 upc xb ldo core
pp1v5 upc xa ldo core
pp3v3 upc xb ldo
pp3v3 upc xa ldo
ppbus g3h - 12.2V
what I found is that there is no nand power supply
no 1.8v, 2.5v, 0.9v
Please give me some tips and help.
Regards09-19-2024, 07:24 AM -
Greetings everyone.
I've been trying to resolve the above problem, I need insight into the next step to take. This will be my first time handling this kind of machine hence, any replacement part will need to be ordered for since I do not have replacement parts.
readings on the MB:
PPBUS_G3H is present (12.23v)
PP3V3_G3H is present (3.27v)
PP1V8_SLPS2R is present (1.7v)
The C-ports behavior:
The port that communicated with U3200 delivered the above readings although the u3900, u3100, u3200 regions warmed up.
However, the... -
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
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