A2141 820-001700

[madrefoca534]

Hello everyone.

I have a MacBook A2141 on my desktop. Here's the story.
The computer wouldn't turn on at first. I discovered a 0 ohm resistor, measuring 0.950 M ohms. R7813. I replaced the faulty resistor, and the computer turned on without any problems. I reassembled and closed it. When I tried to turn it back on, it wouldn't turn on at all. I opened it again, disassembled it, and closed it, and it turned on without any problems. I left it playing videos, lowered the screen, and a few hours later, I opened it again, and it didn't turn on. It hasn't turned on since then. The voltage measurement is 20V at 750-800mA and drops to 100mA. I only have stable voltage on L7660 = 3.3V L7600 = 5.0V L6960/61 = 3.3V

L7813, L7817, L7816, L7814, L7815, and L7811 have the corresponding voltages, except for L7821 and L7822, which are at 0 volts.

The board, without a battery connected, draws 20V at 0.040mA. I don't know if this is normal for this device. Sometimes it reaches 100mA, but then drops to 0, but it always maintains 20V.

I need your guidance, please. Thank you.

 

[2informaticos]

So you've got problems to come back from sleep?
Test the machine disconnecting angle sensor (J4802).

 

[madrefoca534]

No, the first time I turned it on, it went to sleep, and it came back on without any problems.

Now I'm only testing with the battery connected.

What's catching my attention is that when the battery is not connected, the device doesn't turn on at all. The consumption in mA is between 0.40 and 100, and then drops to 0.

 

[2informaticos]

Be aware, this machine requires 96/140W charger to start; if no battery connected.

 

[madrefoca534]

I'm using a 140W charger. What else could I do to test it?

 

[madrefoca534]

A friend lent me a computer with the same specifications, and it's working.
The battery is good. I mounted the motherboard on my friend's chassis and it turned on without any problems. So far, everything is fine.
My suspicions about the battery are coming true. I'll report on the progress.

 

[madrefoca534]

The battery is definitely the problem. I tried it with my friend's chassis battery and nothing bad happened. Everything works perfectly.
I'll replace the battery.

Thanks again for your tremendous help.