Re: Samsung Np350V5C power on, restart 11 times before shutting down. UMA problem ?

Hi,

I have some news. I traced the 2.72v and it goes to :...

Re: Samsung Np350V5C power on, restart 11 times before shutting down. UMA problem ?

I found the 2.12v, it comes from Q29.

When the laptop is OFF (ac adaptator connected), I have :
0 on pins 1 2 3 4
3.30v on pins 5 6 7 8

When the laptop is ON (ac adaptator connected), I have :
2.12 on pins 1 2 3
2.72 on pin 4
3.30v on pins 5 6 7 8

NP-350 la-8861p schematic
[url]https://www.badcaps.net/forum/attachment.php?attachmentid=189822&d=1548940828[/url]Re: Samsung Np350V5C power on, restart 11 times

Re: Samsung Np350V5C power on, restart 11 times before shutting down. UMA problem ?

Hi,

I checked bios chips UH3 & UH4 when the laptop is ON.

For UH3, I have 2.12v to all pins except pin 4, I have 0.
For UH4, I have 2.12v to all pins except pin 4, I have 0.

I have 3.23v on PJP3 and 3.28v on PJ31 when the laptop is ON.
I have 2.27v on PJP3 and 0 on PJ31 when the laptop is OFF.

I have to find this 2.12v now. Where this voltage comes from ? from which chip ? if you have an idea

Hi,

Someone gave me a motherboard and I am trying to repair it.

It comes from a Samsung Np350V5C laptop.
Motherboard model : QCLA4 LA-8861P REV 2.0 with a Celeron processor (for testing) and 1*2gb of ram.

One coil is missing (PL703) on this motherboard. Someone tried to enable UMA.

Problem : each time I power on this motherboard, the motherboard is ON 6 seconds before restarting by herself without shutting down... 11 restarts before shutting down.


The start up button works well, I tried it with another motherboard,...

Re: New Members - please post your introductions here

Hi,

I am Dave from France, 30, I am a beginner and I joined this board to learn things.

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