Repair of ASUS FX63V notebook switch after power failure

VCC was not found when testing ALL_SYS_PWRGD,shorted to ground was found when measuring pu12 6#, and C223 damage was determined by Current heating test.diode value returned to normal after C223 was removed, and PU12 was welded back. After power-up, PU12 6# output a stable 2.5V, and the machine was no longer auto power off.

[machine model] ASUS FX63V notebook

[motherboard model] DABKLMB28A0 REV:A

[Fault phenomenon] The notebook switch is powered off.

[maintenance process]

My colleague sent me an ASUSnotebookWhen the machine presses the power-on button, it is found that the indicator lights up and then goes out immediately. The phenomenon of plugging in the charger is consistent, so it is suspected that it is a motherboard problem.

Asus FX63V notebook switch after power failure maintenance Figure 1

After disassembling the machine, it was found that the BIOS of the machine had been passive, and some stickers were missing. After unplugging auto power off pool, press the power-on button, and it was found that the current went up to 0.10, sometimes up to 0.9 or so and then auto power off. According to the phenomenon, it was preliminarily determined that auto power off was caused by incomplete VCC. The initial test found that the CPU core auto power off was normal, and the rest was basically normal.

Asus FX63V notebook switch after power failure maintenance Figure 2

After checking VCC connected to ALL_SYS_PWRGD, it is found that except +2.5V_SUS produced by PU12, the rest are normal, and the model of PU12 is G9661.

Asus FX63V notebook switch after power failure maintenance Figure 3
According to G9661PDF, G9661-pin is PG, II pin EN, III pin VCC, IV pin VPP, V pin NC, VI pin OUT, VII pin ADJ and VIII pin GND. After the PU12 is removed, the measured machine current reaches 1.2A, which is auto power off. The measured values are 1# 3.3, 2#3.3, 3 4# 5v, 5 # 0, 6 # 0, 7 # 0 and 8 # 0. It is known from PDF that the chip conditions are basically met. When measuring pu12 6#,shorted to ground is found

Asus FX63V notebook switch after power failure maintenance Figure 4

Asus FX63V notebook switch after power failure maintenance Figure 5

After C223 was removed,diode value returned to normal, and PU12 was welded back. After power-up, PU12 6# output was stable at 2.5V The machine stopped using auto power off, and the current trotted all the way. After the display screen was connected, a long-lost LOGO appeared. The test function was all normal, and the fault was eliminated. The maintenance ended here.