820-3476-a powers down

[TBFix]

Hi this board goes to 900mv then drops to 400mv and then to 14mv . The backlight comes on for a split second.
Vcore stays stable at 1.8v

Where should I start looking .
There is no visible liquid damage

 

[2informaticos]

I hope you mean "mA" instead of "mV", no???

Check for USB activity and external video.

 

[TBFix]

Apologies I was sleepy , yes mA not mV . Just before the Back light comes on there is USB activity on external mouse then unit powers off even if nothing is plugged into it.
Theres no external video.

 

[2informaticos]

"Vcore stays stable at 1.8v"
Is impossible with 14mA current cosumption.
Please post accurate information...

 

[TBFix]

Until it drops to 14ma then of course you loose it.
What I meant was vcore is stable.

Does the same in Smc bypass mode

 

[2informaticos]

When is VCORE stable???
Which voltages do you get with 14mA???

 

[TBFix]

Ok just to clarify.
The board powers up and draws 900ma , fan spins Cpu Heats has 1.8v and is stable.
The boards current consumption then begins to drop down to 400ma (Vcore still at 1.8v) and then turns off and sits at 14ma current consumption.
So my question is basically what would cause the board to drop from 900ma ?

I tried in Smc bypass mode and exact same issue.
Any pointer would be greatly appreciated.

 

[2informaticos]

How much time the board stays with 900mA?

Do you get USB activity in this time?
I talk about activity, not just USB power!

Did you try known good BIOS?

 

[TBFix]

It stays a 900ma approx 17 seconds then begins to drop. When it gets to 450ma then I start to get Usb activity (Flickering LED on usb key).

I havent tried a bios yet as but will flash clean one and see what happens.

Thanks for your time

 

[TBFix]

Flashed Clean bios now stay on , just running some diagnostics but looking good. Thanks again for your expertise its well appreciated.