Dell N4050 suspicious death

[berthfield]

Hi, I am new here and would really like is some help could be offered as I have ran out of ideas.

I have here with me a Dell 14r N4050 that died on me a bit suddenly a few months back. The machine was being used, then powered down and when I went back to power it on it would not power up. Pulling it down and inspecting the board shows no sign of failure other than the power and charging LEDs being constantly and dimly lit once current is applied to the board.

It does this with all the user removable components removed, RAM, wifi, CPU etc.

Things I have confirmed so far are that:

1. No component on the board, other than the USB power chip (my stupid mistake), shows visible damage.

2. There are no burnt traces or components getting hot/warm when the board is powered by either the power brick or battery.

3. All the power rails are exhibiting, what I would like to think are, the correct voltages. eg. 5v_s5 = ~4.98 3.3_s5 = ~3.25

4. None of the S0 or S3 power lines are displaying any power or direct paths to ground.

At this point I have ran out of ideas. Can anybody point me towards what I can try next?

Thanks for the help.
A. Berthfield

Edit: Not sure if this is important/relevant in any way but when the charger only is connected all the S5 voltage rails are active, what I found odd was that in that state there is only ~2.5v present on the B+ (battery positive) line.

[samanthban]

Re: Dell N4050 suspicious death

first check whether io communicating with bios .

[berthfield]

Re: Dell N4050 suspicious death

Sadly I do not have access to an oscilloscope as I am really only just getting into hardware repairs. Is there anyway to test this with simple tools?

I am not really afraid of damaging the board as I have already gotten another laptop and have decided to use this board, as well as others, as a platform to learn on.

[samanthban]

Re: Dell N4050 suspicious death

then just flash bios and see .with multim, you cant do that.

[berthfield]

Re: Dell N4050 suspicious death

If I remember correctly I tried that once before. I was unsuccessful though as my DIY programmer (flashprog + arduino mega) was being shorted circuited when connected. I should be getting a hot air station soon so I will try lifting, programming and/or replacing the chip when I get the tools.

I will post my results when I try that. I was just worried that I was overlooking something that was simple/obvious due to my lack of experience.

Thanks for your recommendation.