Re: Macbook Pro A1706 820-00239 No power, No liquid
The cap C7609 is ok. Is it possible U7600 is dead?
A this point I have:
- PP5V_S4 = 28mV
- P5VS4_VBST = 4.8V
- P5VS4_EN = 174mV
- PP3V3_S5 = 0V
- P3V3S5_VBST = 4.8V
- P3V3S5_EN = 3.4V
pin4 of U7600 = 28mV
pin4 of U7660 = 0V...
calamaro
Member
Last Activity: 03-19-2023, 03:49 AM
Joined: 06-13-2020
Location: Milan
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Re: Macbook Pro A1706 820-00239 No power, No liquid
I'm sorry but I made a mistake, the voltage on R7100 is 28mV on both sides.
I made another measure on cap C7609 (you can find it in the image I uploaded before, on the right side of the U7600). On pin1 I have 4.8V and on pin2 28mV. I put the multimeter in diode mode and pin2 is ok but on pin1 I have 0L. I think this cap doesn't work well. Could you confirm?
Thank you...Leave a comment:
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Re: Macbook Pro A1706 820-00239 No power, No liquid
Thank you for your reply disorder. Voltage on R7100 is 0V. I don't understand on schematic where PP5V_S4 is generated. Isn't generated from U7650?...Leave a comment:
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Re: Macbook Pro A1706 820-00239 No power, No liquid
PP5V_S4 is about 28mV, PP5V_SO_EN is 0V, both are NOT shorted to ground (checked in diode mode)
I'm not sure but the problem could be here. PP5V_S4 and P5VS4_EN are not shorted to ground
...Leave a comment:
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Re: Macbook Pro A1706 820-00239 No power, No liquid
I have no problem with PPBUS_G3H so why I should unplug j9600?
I have no pp5v_s4 but pp5v_so_en is ok....Leave a comment:
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Re: Macbook Pro A1706 820-00239 No power, No liquid
Thank you for your reply disorder. Already checked in diode mode and they are not shorted to ground....Leave a comment:
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Re: Macbook Pro A1706 820-00239 No power, No liquid
Thank you so much for your support! No components were moved (I found my hot air station doesn't work so well so I soldered the new cap with the solder).
I found that power rail PP5V_S0 is about 75mV and PP3V3_S0 is 0V. Could you help me to understand where they are generated?
Thank you...Leave a comment:
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Re: Macbook Pro A1706 820-00239 No power, No liquid
Hi guys, I replaced the bad cap and now the U7800 is not running hot anymore but the board doesn't work. I have an usb tester where I see 20V but 0/0.03 A.
PP5V_PMICLD is 5V, PP3V3_PMICLDO is 3.3V.
Do you have any suggestion on how to proceed? Which check I should do?Leave a comment:
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Re: Macbook Pro A1706 820-00239 No power, No liquid
Found the bad cap. It was a nightmare desolder it. I used the hot air gun at 450°C with the flux, I removed it but the lead on both sides was never really melt. Fingers crossed when I have to place the new one.Leave a comment:
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Re: Macbook Pro A1706 820-00239 No power, No liquid
Update: I tried to remove a capacitor with hot air gun starting from 220ºC to 305ºC and with Chip Quik SMD291 Flux but I can’t even move it. What’s the problem? Wrong temperature, flux or what?Leave a comment:
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Re: Macbook Pro A1706 820-00239 No power, No liquid
Thank you piernov for your reply!! I've found the short is on the PP5V_PMICLDO line where I have 2 caps (You find it on the page 78 of the schematic). How could I check which one is broken?...Leave a comment:
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Macbook Pro A1706 820-00239 No power, No liquid
Hi to all guys, like I wrote in the title my macbook has no power problem.
It happened suddenly when I tried to power it on. I inspected the board, obviously no signs of liquid, corrosion or some burned cap. After a bit of troubleshooting I found the component U7800 runs very hot after 4/5 seconds after I connect the plug and it continues to run hot until I remove the plug.
I'm quite sure it could be a short circuit in that component and I ordered it but it will arrive in a month. Is there anything else I could test to be sure there are no other problems? How do you think about... -
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Hello people, I'm a computer engineer with a passion for electronics and repairs. I'm sure to find some useful and expert help here for my next challenge.Leave a comment:
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