khanc0724
Member
Last Activity: 03-13-2025, 09:58 PM
Joined: 03-06-2025
Location: Pensacola FL
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PP3V3_G3H is 0v with power applied. The 4.9v i'm referring to is at R6991 with it removed. When it was still on the board I would only get 1.5V at R6991. Since it's a 0 ohm resistor i'm guessing it was drawing the voltage down.... -
My mistake, correction the EN_VR1 to R6991 not R6999. The voltage drop was at R6991 but when I removed it and tested voltage at pad 2 of R6991 it went back up to 4.9v....Leave a comment:
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Did some more desoldering. I removed U6990. I measured the voltage at U7000 following the boot sequence and noticed that it was 4.9v up until it left from EN_VR1 to R6999. At R6999 it dropped from 4.9v to 1.5v. I removed R6999 and tested voltage at the the pad and got 4.9v. I'm still getting .5v at pad 3 of D6905, not sure if that's relevant. I don't have any new components yet so I can't install and re-check. I am also still getting 12 ohms to ground on pad 2 and now 160 ohms to ground on pin 1....Leave a comment:
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I see what you mean now. Since the fault seems to be on the consumer side, there are too many components to isolate and track down the short. I think I might have reached an end with this one. Seems like a new logic board will be a lot less of a headache at this point :-D...Leave a comment:
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Already confirmed D6905 is bad. Just removed R6999 and no short to ground on L6995 and OL for resistance on both pins. With R6999 removed, can I or should I apply 5V and check the pins again?...Leave a comment:
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Removed R6999. When checking resistance on L6995 I now get OL on both side....Leave a comment:
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I tested the caps again and C6989, C6988, C6996, C6997, C6998, C6995 show shorted to ground. I'm guessing one of them is causing the others to short out too? Any advice on how to test? I am also getting continuity to ground on both pins on L6995, something to check?
Voltage on L6995 pin 1 and 2 is [B]0.3V[/B]
Resistance to ground on L6995 from pin 2 is [B]11.8 ohms.[/B]I tested the caps again and C6989, C6988, C6996, C6997, C6998, C6995 show shorted to ground. I'm guessing one of them is causing the others to short out too? Any advice on how to test? I am also getting continuityLeave a comment:
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Ok, I tested D6905:
Pin 1 - 3 = [B].22v[/B]
Pin 2 - 3 = [B]OL[/B]
Reverse = [B]OL on both pins[/B]Ok, I tested D6905:
Pin 1 - 3 = [B].22v[/B]
Pin 2 - 3 = [B]OL[/B]
Reverse = [B]OL on both pins[/B]Ok, I tested D6905:
Pin 1 - 3 = [B].22v[/B]
Pin 2 - 3 = [B]OL[/B]
Reverse = [B]OL on both pins[/B]Ok, I tested D6905:
Pin 1 - 3 = [B].22v[/B]
Pin 2 - 3 = [B]OL[/B]
Reverse = [B]OL on both pins[/B]Ok, I tested D6905:
Pin 1 - 3 = [B].22v[/B]
Pin 2 - 3 = [B]OL[/B]...Leave a comment:
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PIN 1, 2, and 3 are all [B]OL[/B]. I removed D6905 and I am still only getting [B]3.27v[/B] on pin 3 with [B]5.2v[/B] on pin 2. Should there even be any power on pin 3 with the D6905 removed?PIN 1, 2, and 3 are all [B]OL[/B]. I removed D6905 and I am still only getting [B]3.27v[/B] on pin 3 with [B]5.2v[/B] on pin 2. Should there even be any power on pin 3 with the D6905 removed?PIN 1, 2, and 3 are all [B]OL[/B]. I removed D6905 and I am still only getting [B]3.27v[/B] on pin 3 with [B]5.2v[/B] on pin 2. Should there even be any power on pin 3 with the D6905 removed?PIN 1, 2, and 3 are all [B]OL[/B]....Leave a comment:
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I'm leaning towards that same conclusion. D6905 between pin 2-3 is 1.8v and 1-3 is .22v. I ordered some BAT30CWFILM diodes, hopefully it will fix the issue....Leave a comment:
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Just to make sure I did it right. With power removed, I checked pin 2 on U6990 to ground and pin 9 to ground in diode mode. I got .66 and .72 respectively, whatever that means. Nowhere close to .55 and .35....Leave a comment:
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Should I bridge the two pads from pin 2 to pin 3 and check for voltages again at U6990 and U7000...Leave a comment:
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I did a close inspection of the board but I do not see any physical damage. Not even scratches or nicks. I did notice that when checking the D6905 for resistance, with meter set at 2K I am getting 1.8K from pin 2 to 3 and 190 from pin 1 to 3....Leave a comment:
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I can't find a R0201 on the schematic. My output voltage from D6905 is only 3.3v with 5.05v going in. Voltage at pin 10 of 6990 is 4.12v....Leave a comment:
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Macbook Pro A1708 820-00840 no power
Hi everyone! So my wife attempted to swap out her macbook battery and after she was done the laptop would not turn on. I tried powering on from just the charger and nothing. The battery is good. This is what I have right now after some troubleshooting.
Only taking 5V .2 AMPS
PP3V3-G3H is missing
I have followed the boot sequence and I have good voltages up until I get to PM_EN_P3V3_G3H​, the voltage drops of from 5.1v to 4.2v. After that all voltages are in the boot sequence are 0.
I checked caps and I don't see anything. I tried using the thermal gun and no hot... -
Hi everyone! Looking to get some additional knowledge and help with my repairs. I got the basic knowledge and can do most basic soldering and repair. Hello from Japan!...Leave a comment:
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