Hi Macbook wont turn on fan just on and off ,have green light on charger ,
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Re: Macbook Pro 13 A1278 EMC2555
try making a SMC AND/OR PRAM reset first of everything , then let us know , in case you dont know how to do it
SMC reset require no power on board , no battery and dc attached to machine , for 40 second , during this time press a few times on off button .
pram reset - press command + alt +p +r and keep pressing does keys while you press on off , keep the keys pressed , once you hear the reboot and second chime noise , release all keys . -
Re: Macbook Pro 13 A1278 EMC2555
It not work When I connect charger it constant on off but when is on battery when I press power button makes only 2 sec fan spinning and thats all,black screen no post no beepComment
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Re: Macbook Pro 13 A1278 EMC2555
mainboard code ? 820-xxxx ?Comment
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Re: Macbook Pro 13 A1278 EMC2555
Hi its 820-2879 Intel i7
What Im was thinking that problem is one of the current sensing capacitor ,because its cut power just second after startComment
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Re: Macbook Pro 13 A1278 EMC2555
Sorry correction about logic is 820-2936-BComment
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Re: Macbook Pro 13 A1278 EMC2555
voltages on bios pins ?Comment
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Re: Macbook Pro 13 A1278 EMC2555
3.3vComment
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Re: Macbook Pro 13 A1278 EMC2555
wich pins have 3.3 ?Comment
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Re: Macbook Pro 13 A1278 EMC2555
I have the similar problem, same board...
It came with PPBUS_G3H shorted to GND at Q7035.
I have changed Q7035 ang got green light and fan as well.
But unfortunately I have no display, chime, anything...
Also tried to power on without RAM and it runs in same way, no beeps...
When I plug the charger with battery inserted, green light go off after couple of sec and no orange light came on. So I have SMC_BC_ACOK at U6901 without battery and not with battery connected.
I tried with changing U7000 - same...
On BIOS i have 3.3 at pins 1,2,3,7,8.Last edited by cvorke; 04-28-2016, 11:28 AM.Comment
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Hi All.
I have a very strange issue that I have been trying to fix for a few days now.
Model: MacBook Pro A1278
Logic board: 820-3115-B
Laptop history:
No visible liquid damage/corrosion, but found evidence of other rework (flux) so any signs of liquid may have been cleaned. The laptop went in for a battery replacement but wasn't working afterwards and was deemed unfixable (as told to me by previous owner). Not sure if this was by Apple, or another repair company. The flux found was found around ISL6259HRTZ, so can assume it was replaced... -
Subject: Help Needed: MacBook A1278 (3115) No PPBUS_G3H Issue
Hello everyone,
I'm working on a MacBook A1278 with the 3115 logic board and facing an issue with no PPBUS_G3H voltage. Here's what I've checked so far:- U7000 Measurements:
- Pin 3 has 0V, even though R7012 shows 16.5V from PPDCIN_S5_CHGR.
- Resistors:
- I measured R7010 and R7011 with one leg disconnected, and both tested OK.
Based on these findings, I believe U7000 needs to be replaced. However, I have a related question:- If I also decide to replace the SMC, do I need to order it pre-programmed,
- U7000 Measurements:
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The charging indicator light on my ASUS X54H laptop is always on even when the charger is disconnected.
Windows also shows ''Plugged in'' when charger is not connected.
This problem started year ago gradually, when unplugging the charger the charging light took several seconds to disappear, then minutes, and now almost always on even when unplugged for an entire day.
Strangely, before sometimes immediately when plugging in the charger the charging light went away, and later came back with it connected.
If I let battery run out and say it has 3% Windows will... -
Hello all,
Working on my wife's 13' Macbook air. It's been in a box since she upgraded but I figured it could be good practice.
Details:
Macbook 13' A1466
Board (820-3209-A)
Battery OEM 7.3v 50Wh 6700 mAh (020-7379-A)
Pictures below of Boardview and schematic...
I don't know how to test the voltage on a MacBook battery. I just assumed it had an enable pin but the best I could read was 300 something mV poking around the battery connector.
It's an older model and it is very likely that battery has become... -
Hi everyone!
I have a 2018 MacBook Pro (with Sequoia OS) that I've been using for years with no problem. I recently received an M2 MacBook Pro so I'm mostly using it and not the 2018 one, but since a friend of mine needs a computer, I thought I could restore my 2018 and give it brand-new-like to my friend.
I tried using the built-in tool to restore the MacBook (Settings > General > Transfer or restore > Delete) but it got stuck when trying to remove the Find Device configuration (it asked me for the password for my old Apple ID -now I use the same account but...06-27-2025, 08:54 AM
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