MacBook A1502 notebook is not turn on for repair

Machine model: MacBook A1502

No. 24-820 plate

Fault phenomenon: notebook no booting

Maintenance process: the indicator light of manually inserted adjustable adapter is not on and standby is 0.008a. After the machine is disassembled, the common point VCC 16.5v is normal, and the lower Switch pin 3V VCC is normal (the standby VCC is not tested, the Switch has 3V, and the standby VCC is ignored).

SMC for measuring EC_ONOFF_L pin VCC had current of change, and PM was measured_PWRBTN_When l is 0V, the ground is normal, and the trace is from = pp3v3_S5_Reg, the VCC is set by = pp3v3_S5_Reg is converted.

=PP3V3_S5_Reg is standby VCC(I can’t remember whether there is VCC on standby, but since it is useful here, it must be standby to have VCC) = pp3v3_S5_Reg is produced by u7501, see drawing.

MacBook A1502 notebook is not turn on for repair Figure 1.

Working conditions: 23 pin VIN 16.5v normal, 12 pin en p5vs5_No VCC was found in en, and p5vs5 was traced_EN by SMC_PM_G2_From en, SMC_PM_G2_EN is issued by u5000, which is EC.

Then measure the EC working conditions,VCC vdd, vdda,CLK SMC_Clk32k, reset RST *,VCC are all normal. It is suspected that the EC is broken. Apple EC has programs. If you buy EC, you buy Parts motherboard.

MacBook A1502 notebook is not turn on for repair Figure 2.

The Parts motherboard chip has been removed. I don’t know how to dismantle it. My friend said BGA Rework Station, then BGA Rework Station!Lead free temperature directly dry, the first change did not know this EC to plant beads.On the Internet ordered a Stencil, received directly open dry, to you to see the results.

MacBook A1502 notebook is not turn on for repair Figure 3.

Yes, you’re not wrong. The net has been dried and abandoned, and the planting beads have not been successful. There’s no way to decide. It’s impossible. Let’s put it by hand!

MacBook A1502 notebook is not turn on for repair Figure 4.

MacBook A1502 notebook is not turn on for repair Figure 5.

Then BGA Rework Station is on the computer.

MacBook A1502 notebook is not turn on for repair Figure 6.

Finally, the test, plug in adjustable, boot sound has but not show, is tangled when the screen lit, a white folder with a question mark jump out, a reaction to Nand did not install,Nand again switch perfect.