Three chips for PWR_SRC_NVVDD?

Thread Starter

harrlyald

Joined Sep 14, 2021
15
Hi,
I have a ms-16w11 motherboard which was shorting when adapter was plugged in (light went off on adapter). I started testing and measuring and found a chip named PU15 on the schematic to be problematic. I removed the chip. When plugging the adapter back in, the laptop powers on but the screen does not come on. I assume this is because PU15 is missing. I have attached the schematic. Please could someone tell me why PU15 needs to be present if PU16 and PU17 are doing the exact same job (why are three chips required for the same purpose)?

Thanks in advance.
IMG_20220214_083504.jpg
 

Irving

Joined Jan 30, 2016
3,005
Indeed the three chips are doing the same job,but not all at the same time. What you have here is a multiphase VRM (voltage regulation module), basically 3 buck converters, operating on three consecutive pulses NVVDD_PWM1/2/3 to provide higher power from lower-power components.

Two clearly aren't sufficient.
 

Thread Starter

harrlyald

Joined Sep 14, 2021
15
Thanks for the response.
Would it make sense then that the laptop powers on, does not show any display and powers itself off after a few seconds?
 
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