MacBook A1466 single battery laptop cannot be powered on for repair

Machine model: MacBook A1466

Malfunction: the machine water damage can be charged after processing, and it can also be discharged by unplugging auto power off. It only uses battery laptop Won’t Turn On.

MacBook A1466 single battery laptop cannot be powered on for repair Figure 1.

Maintenance process: 3.42V can be measured when the battery is used alone, and the condition of EC is also normal. According to Switch,current of change can also enter EC, and the condition of the bridge has been checked, and no problem is found. During this period, I changed EC,6259 and brushed BIOS.

Referring to the motherboard of A1465, all pin of U5110 were measured by battery alone, and it was found that 6 pin had 3.42 V, while U5110 6 pin of A1466 had only 0.4V V. I also measured the signal SMC_LSOC_RST_L at the beginning, and it was found that VCC was only 0.4V I didn’t see the VCC pulling up everywhere he went, and I wasn’t sure whether this VCC was normal or not, so I left him alone.

There are few places for this signal to go. Only one Capacitor is removed, and it is still the same. I pulled up a 3.42V for him. It is useless to measure this signal again.

MacBook A1466 single battery laptop cannot be powered on for repair Figure 2.

MacBook A1466 single battery laptop cannot be powered on for repair Figure 3.

MacBook A1466 single battery laptop cannot be powered on for repair Figure 4.

The measured 3.42V was actually pulled down to only 0.3V V. Now I’m sure it’s PCB layer short-circuit current. Cut 6 pin of U5110 and 18 pin of the touch interface and fly another line, and the fault is solved.