Lenovo IdeaPad S400 LA-8952P does not stay on

[mferna14]

Hi, I am working on this Lenovo IdeaPad S400 (MB VIUS3/VIUS4 LA-8952P Rev: 1.0). There is no liquid spill & the motherboard is very clean. The problem is that it turns on, I see the WHITE LED turn on & then after 2~5 sec it just turns off. I get the 3.3v & 5V perfectly. No Components are getting hot, cannot understand what's going on with it. It has the Intel HM70 chipset but cannot see any separate video chip soldered on the board, according the specs the Video Graphics is in this chip. Any help will be greatly appreciated. Thanks in advance.

[Th3_uN1Qu3]

Re: Lenovo IdeaPad S400 LA-8952P does not stay on

Try reflashing BIOS.

[mferna14]

Re: Lenovo IdeaPad S400 LA-8952P does not stay on

Thanks, will flash the BIOS first & if works, will let you know.

[Th3_uN1Qu3]

Re: Lenovo IdeaPad S400 LA-8952P does not stay on

Is the battery any good? If a good BIOS dump doesn't fix it, it could have something to do with either the input mosfets or the charging circuit. I had a liquid damaged board that only started up reliably on the battery and would charge only when it wanted to, and it would turn off randomly. Turned out to be a burnt out trace to a resistor supplying the 3.3 volt chip from the 19V input, took me a good couple days and many more other boards fixed in between to find the bastard. Had a black PCB too... Ugly.

[mferna14]

Re: Lenovo IdeaPad S400 LA-8952P does not stay on

Thanks "Th3_uN1Qu3" I will do the BIOS update.. I see more than two link treads regarding the BIOS Bin files for this model. Do you know which is the right one??? In my motherboard there two BIOS chips.

[mferna14]

Re: Lenovo IdeaPad S400 LA-8952P does not stay on

With the new flashed BIOS., still the same status., Stays on for a while then shuts down. It looks like something else is defective.. Any tips???