UPDATE :
So after a checking around I decided to reflow the SMC as I believe it wasnt starting up. And once I redlowed and cleaned up, I plugged in the charger and viola, charging light!
I then put it all back together and tested and it's coming, charging and working no problem!
Thanks again for the help!
JasonC89
Member
Last Activity: 03-11-2025, 08:29 AM
Joined: 04-13-2023
Location: Kells
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Thank you.
Just got back to testing now.
Both C8010 and R8112 have 0v on them, so looks like its not being enabled?...Leave a comment:
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Macbook Pro A1502 820-4924-A - No Power/Charging Light
So Ive got a Macbook Pro here with no power or charging light.
I have taken the board out and did an inspection and found a small bit of water damage on C1267 (PP1V05_S0). Cap fell off as I cleaned the area but I dont think this is responsible for my no power or light issue, and should probably work just fine without it.
So after watching a few Louis Rossman videos and some post here with similar issues, Ive done a lot of testing and have found the following values of the main lines I think are important:
PPDCIN_G3H = 16.63V
PP18V5_DCIN_FUSE = 16.63V... -
Good taste in music I see
Perfect, I will have a quick look at some boards I have here, if not I will order from a local electronics site, they seem to have the exact correct one (although they have a MOQ of 25 lol).
Thanks again and enjoy your day! (or night lol)...Leave a comment:
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Okay, so I think I have it sorted. Upon testing R6907, instead of 2R2 ,I was getting around 62 ohms, I replaced it with a new resistor, and tested and the charger immediately went to 20V.
Im getting 3.4V on R6923 (while on the board) and Im getting 12.61V on PPBUS_G3H.
D6902 is also bad though, as when I put it back on the board instead of the wire I had for testing, it no longer was getting 20V from the charger and the other voltages also dropped to the old values.
A new diode (need to source a replacement, would windows laptops have similar ones?) and...Leave a comment:
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I tried this and it kicks the charger to 20V.
Current on the charger goes up over an amp and then drops down to almost nothing. (maybe to be expected since it's not taking to the regulator....Leave a comment:
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It's 2.2V when R6923 is on the board.
I'll double check the resistance when I'm back.
(I did notice that when testing one of the left side type c port, the voltage dropped from 2.2v down to 1.7V. I get 2.2V on R6923 on from the other 3 ports....Leave a comment:
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Anything else you suggest [USER="295753"]mon2[/USER] before I send this out?
Thanksmon2Anything else you suggest [USER="295753"]mon2[/USER] before I send this out?
ThanksLeave a comment:
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Unfortunately still the same, which I thought it may be as I was thinking about it last night. I removed diode previously and still got the drop on pin #3 until I removed R6923.
I removed the diode again and ran a wire from pin #1 to pin #3, plugged in charger and I'm still only getting 5v. Pin #3 on D6902 is still getting pulled to 4v, resulting in only 2.2v on R6923.
Could it still be the regulator?
Could 3.4v be injected on R6923 to see if we get 20v on the charger, or is that risky?...Leave a comment:
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Okay I'll try this when I'm back working on it in the morning.
Thank you 🙏...Leave a comment:
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Yeah I may just replace the diode.
I do actually recall it getting hot (using thermal camera) when I first started testing. Found a low resistance on pin 3, that went away when I removed one of the 2 caps on the line.
Jow I just need to find a replacment as I have no macbook boards, but plenty of windows laptop donors.
...Leave a comment:
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Ive done a bit more testing on U6903 just to check voltages coming out.
With R6923 in place :
1. P3V3G3H_VBST = 4.88V
2. PPVIN_G3H_P3V3G3H = 4.14V
3. P3V3G3H_LX = 2.23V
8. P3V3G3H_BIAS = 4.13V
9. P3V3G3H_FB = 0.66V
10. PM_EN_P3V3_G3H_R = 4.91V
With R6923 removed :
1. P3V3G3H_VBST =7.63V
2. PPVIN_G3H_P3V3G3H = 5.01V
3. P3V3G3H_LX = 3.4V
8. P3V3G3H_BIAS = 4.98V
9. P3V3G3H_FB = 1.02V
10. PM_EN_P3V3_G3H_R = 4.99V
Not sure how significant these are but just thought I would test both with and...Leave a comment:
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No worriee, just making sure in my thinking. Yes, if I add R6923 back, voltage drops back to 2.2V? Something must be pulling it down?
Ive checked resistance again with R6923 removed and get over 500k on pin 2 so no sign of anything short that side....Leave a comment:
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me
Okay, so you think U6903 is defective even though after I remove R6923 off the board, pin 3 on D6902 seems to be normal and also pin 2 of L6900 shows the correct 3.4V, instead of the 2.2V I was getting with R6923 on the board?
I thought removing this resistor is isolating the circuit from the rest of the board, and since it seems to be working properly now, the issue must be part of the circuit after R6923 pulling the voltage down?
I may be completely wrong as I think this may be the first macbook board Ive worked on, so Im learning as I go.
...Leave a comment:
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Yes I thought that too, removed D6902 and it still had the same power drop? I then removed R6923 and I got 5V on pin 3 of D6902 (D6902 still removed), I then resoldered D6902 back and the voltage stayed at 5V on the pin 3 output.
testing the resitance of pin 3 D6902, I again around 300k, which again rise slowly as I keep the probe on it....Leave a comment:
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I get about 60k and it rises slowly as I keep the probes on it....Leave a comment:
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Macbook Pro A1707 820-00281 Stuck @5V
So I have an Macbook Pro that came in for no power (I dont do a lot og Macbook repairs). After some testing I found it was only getting 5V with very little current draw, if any.
I searched around for shorts, and didnt find any. No real signs of liquid damage etc.
Following a couple of questions from other members here I was able to further test voltages etc. Im now at a point where PP3V3_G3H is showing, but only at 2.23V.
I have 5v on the Enable pin.
Also the dual diode D6902 is showing :
5.19V @ Pin 1
0v @ Pin 2
4.15V @ Pin 3
L6900...
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