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820-2879-B a returning continiously beeping

L

LaptopRepair

Member
Hello;

I ve got a macbook pro 2010, that continiously gives one peep after each 8 seconds. No beeld on screen

The fan begins to spin directly after plugging the adapter.

I ve tried many other RAMs.

I shut not down after holding pressing the power button for 10 seconds.

The same issue without any RAM memorry.
 
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smiba

smiba

New member
PPDDR_S3_REG and PPDDRVTT_S0_DDR_LDO voltages there? Quite possibly broken traces or damaged PCH/CPU...
 
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J

jadao

Member
Any history, dropped, water damaged, corrosion, bad looking connectors?

Fan should not start spinning right after pluging in adapter because it's not i5/i7 platforms. Are you sure this happens without pressing power button?

Disconnect keyboard and see if fan still spins on its own when pluging adapter.

For 1 beep issue, check if there is any short on I2C sda/scl lines (R5200 and R5201) but could be other issues or missing rails. I would first address the first issue of fan spinning on its own.
 
L

LaptopRepair

Member
I do have no history about the mac. I ve checked the board with the microscope, nothing suspicious.

Fan is starting like I said directly after plugging the adapter. Even unplugging the keyboard it keeps spinning and beeping. But after taking the board out of its case and plugging the board with the adapter, the fan did not spins. But I hear a just a click from the speaker. That s it.

There is no short on SDA/SCL lines.
 
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L

LaptopRepair

Member
How can I power up the board without using the power button? Because checking PPDD_S3_REG and PPVTT_S0_DDR_LDO are on the bottom side of the board?
 
L

LaptopRepair

Member
There are many PP3V42 on schematics. Can you be more specific which one do I need to measure?

On L6995 the resistance to GND is 181 Ohm if that what you mean.
 
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smiba

smiba

New member
Please respond to the thread by posting a full reply

LaptopRepair said:
How can I power up the board without using the power button? Because checking PPDD_S3_REG and PPVTT_S0_DDR_LDO are on the bottom side of the board?
Click to expand...
Short SMC_ONOFF_L to ground to simulate a power button press- But these boards should power on when you plug in the charger by default.

LaptopRepair said:
There are many PP3V42 on schematics. Can you be more specific which one do I need to measure?
Click to expand...
Just any really, they should be connected. But make it yourself easy and probe a bigger sized capacitor or coil on PP3V42
 
D

dukefawks

Administrator
Because PP3V42 powers the RTC circuit in the MCP and I have seen dozens and dozens of these boards with this exact problem.
 
D

dukefawks

Administrator
Yes "new" the Chinese new. MCP89MZ is nowhere to be found real new. Seeing that these chips are all pulled from liquid damaged boards the chance of your "new" chip being dead is about 50%. I do not waste my time anymore on these.
 
L

LaptopRepair

Member
Ok. Some of you said the issue is a dead MCP, other said CPU or both. I am planning to buy one MCP. The customer has aggreed on this. But before making this step, I want to be sure that indead the problem is the MCP and not the CPU.
So please can you give some test point where to know for sure who is responsible for this?
 
D

dukefawks

Administrator
Last time, this is a dead MCP. Also this is a time waster, don't waste your time/money if you have other things to do.
 
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A

aprendiz

Moderator
If you don't believe in the advices given here, the next step is to take the risk and get your own conclusions.....
 
L

LaptopRepair

Member
aprendiz if you read carefully my question you will clearly understand that it has nothing to do with believing or not of the advices given here on this forum!!

The main point of being member of this forum is not just waiting for getting answers and following them blindly eternally. I ve a brain, and some basic knowledge on lapto chip level (not on Apple). So I m trying to learn something from the advises given here.

I am someone who does not want to remain eating fishes got from others, but I prefer to be taught how to fish. ( like the chinese ever said).
 
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