I am working on MacBook 12" A1534 2017 820-00687-B assuming that the logic board is same as 820-00244-B. It was not powering on. I did a ultra sonic cleaning of the motherboard since I saw some traces of liquid spill. Tested out of the casing, all worked fine & display was working 100% well. When I installed it again, no display. So I again was removing the logic board & while removing the keyboard connector I saw little smoke off the connector. I started to check the voltages again. 3.3volts is perfect but 5 volts rail fluctuates on & off on coil L7670 (PP5V_S4)., 5V come & goes again. I did not find any short to ground on this rail. Any tips or guidance will really be appreciated. Thanks in advance.
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Last edited by mferna14; 04-27-2021, 05:08 PM. -
Re: MacBook 12" A1534 2017 820-00687-B
Anyone there to help... Thanks -
Re: MacBook 12" A1534 2017 820-00687-B
Remove the keyboard / trackpad cables.
Check the EN pin on U7650 - does it also toggle ON / OFF with the pulsing of this rail?
Check the components on pins 7 & 8 on U7650. Anything missing ?Comment
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Re: MacBook 12" A1534 2017 820-00687-B
Thanks "mon2" will do so & report... thanks for the helpComment
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Re: MacBook 12" A1534 2017 820-00687-B
Ok 'mon2"., on the EN1 pin of U7650 (PM_SLP_S5_L) the voltage toggles on & off, even on pin 7 & 8 same thing voltage toggles.. But EN2 (S5_PWR_EN) pin 21, here the voltage is constant 3volts, this is why I am getting the 3.3v perfectly. Next to check I think "PM_SLP_S5_L" from where it genereating or some rail. Please inform me.. ThanksComment
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Re: MacBook 12" A1534 2017 820-00687-B
1) PM_SLP_S5_L is generated by U0500, ball BH14 - sheet 15/67 of the PDF.
2) What is the voltage on PM_SLP_S5_L ?
3) With the power off, battery removed, what is the resistance to ground on L7670, pin # 1 ?Comment
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Re: MacBook 12" A1534 2017 820-00687-B
2) What is the voltage on PM_SLP_S5_L ? nearly 2.9 & then drops
3) With the power off, battery removed, what is the resistance to ground on L7670, pin # 1 ? 350.5k ohms & its keep on decreasing ohmsComment
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Re: MacBook 12" A1534 2017 820-00687-B
Do think the CPU got defective???Comment
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Re: MacBook 12" A1534 2017 820-00687-B
The CPU may be defective as reported by more seasoned techs on this forum but hate to believe it. It is a show stopper of an issue if true.
Our fancy BGA rework station should land next week and we are looking forward to complex repairs like CPU rework / reflowing. Has multiple HD vision cameras to perfectly align the balls once we clean the drop site.
2) What is the voltage on PM_SLP_S5_L ? nearly 2.9 & then drops
What is the voltage reading once this rail settles ?Comment
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Re: MacBook 12" A1534 2017 820-00687-B
Thanks "mon2"
"What is the voltage reading once this rail settles ?" the voltages never settles & it keeps on toggling on & off...Comment
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Re: MacBook 12" A1534 2017 820-00687-B
Mr. "piernov" any thoughts on this repairs... Hope you can give me some good tips. Thanks in advance.Comment
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Re: MacBook 12" A1534 2017 820-00687-B
I know its an old post but did you manage to find what was it? I have the exact same problem pp5v_s4 make spikes every so.Comment
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Re: MacBook 12" A1534 2017 820-00687-B
This was a 11" Apple laptop, you know I could not find the problem, eventually I purchase a new motherboard, got for $200, worth it. You look for a new motherboard too, very difficult to find where the problem would be. ThanksComment
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The laptop is Apple Macbook A1534 2017 with board 820-00687-А. The USB-C tester shows no voltage, there is 820-00244-А board available. I looked at both schematics, all connector signals seem to be the same. Did someone try to fit 820-00244-А board in A1534 2017?05-11-2025, 01:08 AM -
Hello there
I have problem with Macbook Pro 15" 2017, model 2017, MB code 820-00928.
I bought it as broken with some artefacts on the screen, first I thought that this is problem with ribbon cable but after inspectiing ribbon cable I know it is fine. I tried to reinstall macOs and then I figured out that this must be something with GPU as installation freezes at the end (when drivers are loaded). I installed Windows and was able to install every each of drivers except GPU driver, as soon as I tried to install GPU driver - black screen and restart.
...11-21-2024, 05:25 AM -
Hi, I'm Daniel, and I'm new to the world of repairing motherboards.
I would like to create a table, or more likely a guideline about the voltage rails and their possible resistance rail.
I know that the motherboard design has a very big depend on the rail's resistance, but I would like to know what is the smallest value for a rail that can be acceptable. For example, I heard that some new gaming motherboards can have 0,5 Ohm resistance on the GPU rail, but on an older type, it could be a sign of a shorted GPU rail.
So, I generated a table with AI so I can... -
Hi All,
i got one Macbook a1534 boardnumber 820-00244 that is taking only 5V 0,2A
I've tried to replace 3x CD3215B01 chip but it's still behaving same ....
On the board there was blown L4804 so i've replaced it.
when power is connected 5V 0,2A
PPBUS_G3H - 0V
PP20V_USBC_XA_VBUS_F - 5V
I've tried to remove F7040 as mentioned here
https://www.badcaps.net/forum/troubl...1534-820-00244
but there is... -
I am looking at an A2337 and found this for the order of power rails and what they do. Can this be confirmed before I dive into hunting down power rails that do not exist or are not neccisary?
- PPBUS_G3H (12.6V-12.8V)
- This is the main power rail that supplies power to the entire system. Check this rail first, as it must be present for other power rails to work.
- PP3V42_G3H (3.42V)
- This power rail is derived from PPBUS_G3H and is used to power the SMC (System Management Controller) and other essential circuits. It should be present if PPBUS_G3H is working correctly.
- PPVRTC_G3H (3.3V)
- This
- PPBUS_G3H (12.6V-12.8V)
Comment