lenovo g780 (LA-7983P) no power no charge

sebuncle

Hi ,
laptop is dead no sign of life ,i tried other bios nothing change.
power come to PQ301 and PQ302
There's no +3VALWP
what i have to check ?
Best regards

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2N3904

sebuncle писал(а):

what i have to check ?

Voltages at:
B+
+3VLP
VL
and check the resistance between +3VALWP and GND.

sebuncle

Hi ,

B+ = 20v (take on PJ401)
+3VLP = 3.3v (take on pin 8 PU401)
VL = 5v (take on pin 17 PU401)
resistance between +3VALWP and ground is 9 ohm (i think it's not correct ?)

I don't see any hot component

Best regards

2N3904

sebuncle писал(а):

9 ohm

It looks too low.
You can find where short circut is, using regulated power supply unit, if you know how to do it.

sebuncle

2N3904 писал(а):

sebuncle писал(а):

9 ohm

It looks too low.
You can find where short circut is, using regulated power supply unit, if know how to do it.

i apply only 3v on pin 1 with 0.5A , and 1A , and 1.5A and... , so i'll find short it's right ?
Thanks

Best regards

2N3904

sebuncle писал(а):

it's right ?

Yes, that's right.
---------- Добавлено спустя 1 минуту 25 секунд: ----------
The damaged component will be heated.

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lenovo g780 (LA-7983P) no power no charge

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