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08 Jul

This article is for MacBook logic board component-level repair professionals, written by IT-Tech Online, the MacBook repair specialist in Melbourne, Australia.

Mac data recovery from a malfunction MacBook Pro, MacBook Air or iMac used to be a simple task as all those Apple computers come with a removable HDD or SSD drive. We can remove the HDD or SSD drive from the faulty Mac and put it into a working Mac and start the data transfer process straight away. Sometimes we need some data recovery software to assist the data transfer process. In extreme cases, we need to replace the data read-write head or the control board inside an HDD drive. Armed with these tools and techniques, we don’t have to know how the HDD/SSD internal circuitry work and still can achieve a high data recovery success rate. Unfortunately, these Mac data recovery methods will not work on the new MacBooks.

Started in 2015-16, the new MacBook logic board designs have shifted from the removable HDD/SSD drives to the none-removable SSD chips. According to Apple, integrated SSD chips on the logic board will increase the data transfer speed, data security of the new devices. On the other hand, retrieving data from these logic boards with onboard SSD chips becomes a challenging task, especially from a water-damaged MacBook. Nowadays, we have to understand how the SSD circuitry works in order to achieve a certain success rate.

The Mac data recovery technique we discuss below can be applied to 2016 to 2017 MacBook Pro touch bar models including the 13″ A1706 and 15″ A1707 MacBooks. IT-Tech Online provides leading Mac data recovery services in Melbourne and offers mail-in services all over Australia.

History of the water-damaged MacBook Pro with touch bar

The customer has spilled a glass of water on the keyboard of this 15″ MacBook Pro A1707 with touch bar. The MacBook worked for a while and then powered off automatically. Since then the customer could not power up the MacBook any more. He took the laptop the Apple store. The genius bar technician told him the logic board of this Macbook Pro is faulty and there is No Way to retrieve the data from the dead MacBook Pro. He has got the same story from six other computer repair stores before coming to us. The data in this MacBook is very important to the customer. Unfortunately, he did not have a backup of the data. This is the reason why he didn’t give up searching for help.

Inspection of the water-damaged MacBook Pro

The logic board CPU core power supply is shorted to ground. The CPU has been killed due to a high voltage directly applied to it. The CPU core power rail MOSFET QA640 and lifeboat port J9600 has been burned. The screen and keyboard are also damaged. This mac is not economically repairable. Our task is to recover all the data from the onboard SSD chips of this dead logic board. This is a 15″ MacBook Pro touchbar A1707 manufactured in 2016 and the logic board part number is 820-00281.

There is a port named lifeboat on the logic board of this 2016-2017 MacBook touch bar model. The port is designed to recover data from the dead logic board. We don’t have to repair the whole logic board as replacing the damaged CPU is very difficult and expensive. Instead, we only need to repair the SSD circuit section of the logic board. Once the SSD circuit and the lifeboat port are repaired, we can connect the data recovery tool to the logic board and retrieve the data, hopefully.

How does the Apple data migration toolkit control the onboard SSD chips in a MacBook Pro with touchbar?

Below is the electronic diagram ( Apple schematics 820-00281) of the lifeboat port in a MacBook Pro touchbar A1707. In a working Mac logic board, there is a special cap covering the lifeboat port. So the PCH (Platform Controller Hub) on the left-hand side can communicate with the SSD chips on the right-hand side via the lifeboat port. We have a separate article “How does the PCH communicate with the SSD circuit in a Mac logic board” on our blog to discuss the working principle of the SSD circuit. Here we emphasise on how the Apple data migration toolkit (076-00236) works.

MacBook Pro touch bar A1707 lifeboat circuit diagram

As long as the SSD circuit of the dead logic board is not damaged, we can remove the cap of the lifeboat port and insert the Apple data migration toolkit to the port to retrieve the data. Once we power on the toolkit and connect it to a working Mac ( the one we use to read data from the dead Mac), the toolkit will perform the following tasks by sending these control signals and power rails to the dead MacBook. Then the toolkit will finally take control of the SSD NAND chips on the faulty logic board and we can start the data transfer process.

  • The Apple data migration toolkit (076-00236) sends SSD_PWR_LB_EN control signal and PP3V3_S5_POLARIS 3.3V power rail to enable and power up the SSD power management IC ( Polaris PMIC) u9300. PMIC u9300, in turn, creates 11 power rails to power the SSD controller chip u8605 and four SSD NAND chips u9100, u9110, u9200, u9210. These SSD NAND chips contain the user data. Our task is to retrieve the data from these NAND chips.
  • The toolkit then sends SSD_RESET_LB_L to initialize SSD controller u8605. In turn, u8605 sends SSD_CLKREQ_LB_L requesting a system clock.
  • The kit sends 100Mhz clock PCIE_CLK100M_SSD_LB to SSD controller and four SSD NAND chips on demand.
  • The kit utilizes a pair of PCI_E buses PCIE_SSD_R2D_LB and PCIE_SSD_D2R_LB to communicate with the SSD controller requesting data transfer from the SSD NAND chips.
  • The toolkit takes over all the SSD power and controller functions previously required from the CPU/PCH. So there is no need to fix the CPU.
MacBook Pro touch bar A1707 logic board schematics and board view

How to Repair the MacBook Pro logic board?

  • As the lifeboat port connector has been destroyed, we need to remove it and replace with a good connector. A micro-soldering skill is needed for this job.
  • Use a multimeter to measure the main power rail PP3V3_S5_POLARIS of u9300 and make sure it is not shorted to ground. A shorted circuit on this chip will not only damage our data recovery toolkit but also need more investigation and repair into the power rails of the SSD circuit. Luckily, all the power rails of the SSD circuit are working. This saves us a lot of time. It is amazing that we still can get an easy job after so many stores failed to repair it.
  • Clean and measure the three pairs of PCI_E buses to make sure they are functional.
  • Connect the kit to the lifeboat port of the faulty logic board and power up the equipment.
  • Connect the USB-C cable from the kit to a working Mac, the SSD drive on the flawed logic board is shown up as an external drive on the screen.
  • Double click the external drive icon, enter the user’s password, the SSD drive in the dead logic board is accessible as a normal external drive now.
  • Open the user folder and transfer all the data to our MacBook internal drive. We need to transfer the data out of the dead logic board as soon as possible. Sometimes there is only a small window opportunity for us to retrieve the data from the unstable logic board.
The data recovery kit is inserted into the lifeboat port of the logic board

Note:
J9600, u9300 etc. are the chip number on Apple logic board electronic circuit diagrams (schematic 820-00281).

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If you are in need of mac data recovery,  get in touch now to find out how the team at IT-tech can help you.

This article is written by IT-Tech Online, the MacBook repair specialist.

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