Hello, I'm new here, but I recently started to deal with the repair of MacBooks. The problem is this, the MacBook does not turn on the first time, you need to press several times, the fan will scroll for a second, the power-on sound appears and that's it. Where to dig? What can be connected with? voltage jumps on CHGR_LX1, at first 12v is unstable, then drops to 0, rises to 12, drops to 4.1v, sometimes to 3.7v
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A2289 820-01987 after the startup sound it turns off
- Thread starter Saifulla
- Start date
First of all, welcome to the forum!
Post F7000 voltage.
Post F7000 voltage.
12.5v stable
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After chime sound, check if you get voltage on big coils.
Also check USB activity and external video.
BTW, any reason to quote an entire post, visible few centimeters above?
Write directly into Reply box, do not click Reply button.
Please, maintain forum aesthetic...
Also check USB activity and external video.
BTW, any reason to quote an entire post, visible few centimeters above?
Write directly into Reply box, do not click Reply button.
Please, maintain forum aesthetic...
That's all?
I said something about USB activity too.
Also EXTERNAL video; is that you've checked???
I said something about USB activity too.
Also EXTERNAL video; is that you've checked???
0.6V on VCORE, looks like board boots.
How do you plan to diagnose a machine with no video problem???
Read this, about what I said in previous posts.
boards.rossmanngroup.com
How do you plan to diagnose a machine with no video problem???
Read this, about what I said in previous posts.
HOW TO collection
I hope this "How to" collection will help our members. I will possibly modify this post in time, if updates available. Trigger SMC_ONOFF_L (PMU_ONOFF_L): It reffers to simulate power button function, when the keyboard is not connected. We need to do this when we work with the board...
boards.rossmanngroup.com
When you repair a board which doesn't get video as the only problem, don't you have another way to check if the rest of the board works good?
Turning on and booting is not the same thing.
Board can turn on but doesn't boot.
In such case there is no activity at all; no internal/external video, nor even USB activity.
How do you know if your board is in this case?
If the board boots and doesn't have internal video, there should be at least USB activity, even external video in many cases.
Turning on and booting is not the same thing.
Board can turn on but doesn't boot.
In such case there is no activity at all; no internal/external video, nor even USB activity.
How do you know if your board is in this case?
If the board boots and doesn't have internal video, there should be at least USB activity, even external video in many cases.
Did you really read the above linked thread???
Did you ever connect an external monitor to a MacBook?
Get an USB-C hub; it has normal USB and HDMI connectors.
Please, pay atention to the posts...
Did you ever connect an external monitor to a MacBook?
Get an USB-C hub; it has normal USB and HDMI connectors.
Please, pay atention to the posts...
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Don't get L7210/20 voltage again?
In the previous posts, you've said to get L7210/20 voltage and sound when connect the charger.
What happened???
What happened???
L7210/20 voltage (VCORE) should drop to 0.6V when board boots; it starts with 1V or bit more.
This voltage remains steady, or disappers after the power on sound?
This voltage remains steady, or disappers after the power on sound?