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Good morning, I’m having a problem with this circuit board from a Lenovo IdeaPad 330 laptop. I’ve already measured the connector input—where it charges with the charger—and sometimes it reads 20V (normal), and other times 0V; I measured the MOSFETs (6414A and 7408—both from Alpha & Omega Semiconductor) between drain and source: beep; between drain and gate, the reading was 0.97 (continuity scale). When I took these measurements, a spark jumped across these MOSFETs. The PU301: all pins are measuring as expected. The PU401: when I measured it (with the MOSFETs already damaged), one of the pins read 19.8 V—the same voltage as the power supply—and the other pins read 0; then it also sparked (perhaps I touched the probe to two pins at the same time), and after that I no longer saw the 19.8 V voltage. UC3 - FLASH MEMORY: Pin 8 (VCC) is reading 0 V. I started investigating why my laptop wouldn’t turn on—not even the power light came on—whether it was connected to the charger or not; Now, given all this, besides replacing the MOSFETs, the PU401, and probably the UC3, what else do I need to do? What other measurements should I check? I’m a beginner. Thanks in advance to everyone for your answers. |
1 hour, 5 minutes ago |
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