Hi all
At first iam not very expert at board level or electrical enginering so apologize if i give a bit not accurate information about it
i was troubleshooting a laptop that wont turn on
The laptop is lenovo G485
At fist time its indeed turning on but no post
After a while its not turning on at all just like something shorted at the board.
Then i checked motherboard and i found a weird low restistance (10-15ohm) at the inductor near power supply connector. I search again for another inductor all over the place.
And this low resistance does also present in the inductor that connected to cpu. I lift one side of this inductor. And check the cpu rails side still giving low resistance, while the other side are not (1 big megaohm) all over rails till the inductor near power supply connector comes normal
I try turn on the board with inductor lift up. It did turning on for sec and turn off
And when i resolder the inductor and connecting dc power (without trigering on the board) it did like pulling power and some mosfet getting hot also the cpu a bit warm.
My question is this cpu shorted? Because I do found information that some cpu/gpu chip have normal low resistant even below 5 ohm (count without resistance of the probe it self)
At first iam not very expert at board level or electrical enginering so apologize if i give a bit not accurate information about it
i was troubleshooting a laptop that wont turn on
The laptop is lenovo G485
At fist time its indeed turning on but no post
After a while its not turning on at all just like something shorted at the board.
Then i checked motherboard and i found a weird low restistance (10-15ohm) at the inductor near power supply connector. I search again for another inductor all over the place.
And this low resistance does also present in the inductor that connected to cpu. I lift one side of this inductor. And check the cpu rails side still giving low resistance, while the other side are not (1 big megaohm) all over rails till the inductor near power supply connector comes normal
I try turn on the board with inductor lift up. It did turning on for sec and turn off
And when i resolder the inductor and connecting dc power (without trigering on the board) it did like pulling power and some mosfet getting hot also the cpu a bit warm.
My question is this cpu shorted? Because I do found information that some cpu/gpu chip have normal low resistant even below 5 ohm (count without resistance of the probe it self)
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