Apple computer A2142 does not boot (hard disk power supply is damaged)

Apple computer A2142 does not boot (hard disk power supply is damaged)

During normal use, this machine suddenly turned off with a black screen. After preliminary maintenance, the motherboard was not obviously damaged and missing parts were missing. After re-inspection, it was found that the fault was damaged for the hard disk power supply. The specific maintenance process is as follows:

“Machine model” Apple computer A2142

[Fault phenomenon] No boot.

[Maintenance process]

Receive an applenotebookComputer A2142. The customer said that the notebook has been kept at home for drama, but it suddenly stopped working some time ago. Because the utilization rate of the notebook is not high, it is now sent for repair. I hope we can help repair it.

Apple computer A2142 does not boot (hard disk power supply is damaged) Figure 1

After you get the notebook, first try to plug it in and see if it can be turned on. After you confirm whether it will be turned on or not, take the machine apart, and take out the motherboard to see if there is any obvious damage and missing parts. This kind of damaged machine in normal use can sometimes easily find the fault point. After checking the motherboard, it is found that the motherboard is clean and there is no place where it is burnt black and moldy, but there is a lot of dust near the fan, which is not a big deal. It is good to clean the dust when it is installed.

After checking the appearance, turn on the multimeter, and use the resistance file to check the resistance of the inductors on the motherboard. Immediately, the fault is found-the resistance of the 2.5v power supply inductor of the hard disk is a little low, which is basically close to short circuit, which is a common fault of 2142. The hard disk is easy to break down. After finding the fault location, we can directly conduct thermal imaging. The burn-in diagram is as follows:

Apple computer A2142 does not boot (hard disk power supply is damaged) Figure 2

Apple computer A2142 does not boot (hard disk power supply is damaged) Figure 3

It seems that this hard disk is damaged, so we directly removed the bad hard disk and replaced it with a new hard disk. Then we tried to connect the computer and found that the current had reached more than 100 ma at this time, and we could connect the computer to DFU mode. We directly brushed the computer and reported an error of -1.

Don’t panic at this time, we are a single-board brush machine, and an error of -1 means that an error will only be reported if the external screen or touchpad is not plugged in. No other code means that there is no problem with the hard disk. We will directly install the motherboard and brush the machine again. At this time, it can be brushed perfectly, and the familiar Apple logo lights up, which means that the problem has been solved.

Apple computer A2142 does not boot (hard disk power supply is damaged) Figure 4

Apple computer A2142 does not boot (hard disk power supply is damaged) Figure 5

[Maintenance result] After the machine is installed, the functions of testing sound, network, recording and playing video are all normal, and there is no abnormality in playing video for a long time. The fault is perfectly repaired, and the maintenance is over.