A2289 820-01987 MacBook will not boot, but does step up charging.

[mgladin]

Hello,

I have a MacBook that was taken to UBreakIFix for a battery replacement. However, they couldn't get the computer to boot even with a new battery and diagnosed it as a motherboard issue, sending the customer on their way. The customer then brought the MacBook to our store.

Upon checking it in and starting the diagnostic process, I found a consistent 0.3A draw. A visual inspection of the board revealed that components DZ3302 and DZ3352 were physically damaged, with parts missing. I replaced these components using parts from a donor board, which resolved the 0.3A draw issue.

However, a new problem emerged. The computer will not boot, but it will stair-step charge, reaching about 1.4A-1.5A at 20W before resetting and repeating the process every 30 seconds. Using a thermal camera, I identified two hotspots: one at L7030 and the other at Q7030.

Upon further investigation with my multimeter, I found no issues with the inductor but discovered a potential short to ground using diode mode on CHGR_LX1 when testing the test point below Q7030. Switching to Ohms mode, it read 2.0-2.1 ohms. I replaced Q7030 to rule out issues there, but the problem persists.

I’m unsure of the next steps. I could try replacing U7000 on the top side of the board, but I can't confirm anything since the short detection in diode mode and parts heating up only occur with the battery connected.

Any advice would be greatly appreciated. Thanks in advance for your help!

 

[2informaticos]

You've said the battery is charging.
Do you really think that is possible having problems with U7000, or Q7030???
Put some logic on your job!

If the machine was booting before battery replacement, I suspect to have more damaged components from the previous workshop.

Is the machine recognized into DFU now?

 

[mgladin]

The device was not turning on at all when she took it to the other shop. They replaced the battery and it did not boot, so they returned everything as it was dropped off and said it was a motherboard issue. Called the shop and spoke to the tech to confirm and found they did not test the device before or after the repair.

I did connect the MacBook to Apple Configurator and I have no signs of DFU.

 

[2informaticos]

Use external switch method to enter DFU mode.

DFU Mode Restore (Macs) - LogiWiki

We have Apple MacBook and iPhone Diode readings and general fault finding information compiled by the leaders in this area

logi.wiki

To confirm if battery is really charging, monitor PPBUS_G3H voltage during 10-30s.

Write into bottom reply box, instead of clicking Reply button.
I don't see any reason to quote an entire post, visible few centimeters above.
Please, maintain forum aesthetic...

 

[mgladin]

PPBUS_G3H starts at 10.3ish volts when it starts charging and goes up to 10.9-11v at its peak while stair-step charging occurs through the charging port. When the stair step charging resets, it will jump to 12.5-13v on PPBUS_G3H and then drop back down to 10.3ish volts and start the process over again. I can record and upload a video if that would help.

Also, I was able to get the computer into DFU mode and recognize it on Apple configurator.

 

[2informaticos]

So battery is indeed charging.
Ask client if there is any important data on SSD.
If not, go for DFU Restore.
If client still hopes to save data, just do DFU Revive.

Explain to the cleint, sometime only Restore (erasing SSD) can help.

 

[mgladin]

Ok, so I know this has taken some time, but I am back again, this time with more info. I tried to restore from DFU mode but was unsuccessful. The customer requested a new motherboard, so we ordered one. Came in, did not work. We sent it back and ordered a new one, same issue. We tried replacing the battery, but no luck.

The MacBook is charging, but shortly after booting it up, it shuts off and drops down to almost 0a draw. Since this is the third motherboard, we are fairly confident that the issue exists somewhere else, but not entirely sure where. We have disconnected everything other than the battery and the issue still persists. We have tried with a known good battery as well as the old one. We have tried with everything connected to the board and everything disconnected, including the screen, except for the battery.

The video I am sharing is with a new battery (known good, we just used it to test a different A2289 last week), and only the screen is connected. When I boot up the computer, I connect the flex ribbon for the power button and that is the only thing that is plugged in other than the screen and battery when we boot up.

I have no idea what the issue is, but maybe I am overthinking it. Let me know if anyone has had a similar issue and what the resolution was. Thanks in advance!

 

[Clever1]

long shot; could it be the power button sticking?

 

[mgladin]

I don't believe so. We have left it unplugged and did prompt to boot through only the charging port and the issue still exists.

 

[2informaticos]

This board requires good battery connected to boot properly.
Also trackpad should be connected.
It should boot without any other connections.

What error do you get on DFU restore?

 

[mgladin]

The issue resolved itself after I replaced the trackpad. My best guess is it was damaged when the last shop initially replaced the battery. Thanks for the info! Did not know the trackpad was required.