Dell Laptop Inspiron 5379 shuts down at start up.

tttleader

Member (✔)
Anyone here specialized in dell laptops ?
I'm working on a laptop that when powered on , shuts down after 5 seconds and repeats this each time it's powered up. You can hear the HD spinning until the lap shuts down. The fan doesn't spin at all. VCC_CORE , +VCCGT , + VCCSA remain 0V and PWM's at pin 4 PU4701, PU4702 , PU4801 (NCP81382) is 2.0V (Mid state) for 5 seconds at power on and drop to 0V and PWM at pin 2 PU5001 (NCP81253) remains 0V. What I noticed is that CPU pin E32 line which is VCC_SENSE connected to pin 47 from PU4601 (NCP81218) measures 3.5R to GND and if I split the line the short remains at CPU side. Can I conclude that CPU has a short ? Need to figure this out because a new mb is about $350. Thank you.
 

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tttleader

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Thank you very much for your replies.
Under this nr I got the schematic : 13-5379 17810 Starlord ROR-L A00 (pages 7 and 46)
3R5 sounds pretty low to me if I compare it with the other sense lines (VCCGT_SENSE and VCCSA_SENSE, which measure about 2.K with diode test, but I'm not familiar with this laptop.
What else can be the problem, that prevents the 1x2x1 PWM NCP81218 chip from driving the power fets ?
 

tttleader

Member (✔)
Thank you very much for your replies.
Under this nr I got the schematic : 13-5379 17810 Starlord ROR-L A00 (pages 7 and 46)
3R5 sounds pretty low to me if I compare it with the other sense lines (VCCGT_SENSE and VCCSA_SENSE, which measure about 2.K with diode test, but I'm not familiar with this laptop.
What else can be the problem, that prevents the 1x2x1 PWM (NCP81218 chip from driving the power fets ?


Does the VCC_CORE appear in a short of time .
The VCC_Core doesn't appear at all.Not even a start up pulse.
 
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