Dead Motherboard Or.....

Hi,

Please be patient with me as I am self taught in the world of IT and unfortunately I do not know everything.

I'm working on a laptop that I was told kept getting the BSOD. Of course they can't tell me any details from the screen. She'd recently had the hard drive replaced as she was told this is why the BSOD was appearing regularly. The laptop is a Sony Vaio PCG-71211W.

The problem I have is the laptop will not power on, no lights, nothing.
The green light does come on the power supply but after leaving it plugged into the laptop overnight it is barely warm to touch.

What I have tried:
Removed battery, unplugged power, held down power button for 30 seconds.
Removed RAM, one stick at a time.
Made sure hard drive was seated correctly.
Used my multimeter to check voltage on power supply and dc jack which were fine.
Disassembled laptop to look for anything obvious that could be causing the problem.

There are two things that concern me.
1). There are spots of rust located under the bezel that houses the keyboard and the touchpad. The motherboard also shows signs of some residue
2). The dc jack to motherboard voltage is okay but the power supply connector does not fit snugly, it definitely wiggles slightly.

As the owner hasn't used this laptop much since the new HDD was installed she was still able to power it on, even though she had the BSOD. She last turned it on 2 months ago but when I first tried to turn it on, nothing, completely dead.
Is it possible a spill of liquid through the touchpad has shorted the motherboard even though she had power 2 months ago but I don't?

I'm attempting to attach photos of the residue/rust.

If you're still awake after reading this, any guidance would be greatly appreciated.

Thank you.

 

From what you've described, I think your suspicions about the spilled liquid are correct and the system board is toast. It also seems that someone was a bit careless when unplugghing the power adapter from the laptop hence, the "wiggle".

 

Nobody does - in spite of what some may think. In fact, if you are realistic and not an egotist, you quickly realize the more you learn, the more you realize there is yet to learn. IT is many industries within industries. Regardless how extensive your education and experience, you will never come close to knowing it all.

I agree with mdonah and your own suspicions - it looks like something was spilled on the notebook or it was just left in a very wet/humid environment. It is not "rust" (as that implies ferrous materials) but certainly could be corrosion, or possibly some form of mildew of fungi. Either way, not good.

You could try to clean it up with electrical contact cleaner and soft scrub brush.

Does it power up with the battery removed? Broken power connectors are a common problem and typically pretty easy to repair. Often, they just need the prongs or tensioned contacts to be bent back into place (though that is generally a temporary fix). Or retouching the solder joints in the jack can fix bad joints. You will need to do a visual inspection to verify that.

I wonder, however, who replaced the hard drive? And what was the status of the notebook after replacing it?

 

Thank you so much. I really appreciate your comments. Being a mum of young twins in what I would call a male dominated industry, can be at times, shall we say interesting. Unfortunately for me I'm like a dog with a bone. Sometimes you cannot 100% confirm why a computer has done what it's done and that's sooooo frustrating. I do love it though. I don't, however, getting up at 3am because I've thought of something else to try on a dud computer
Anyhow, getting back to your questions. No it doesn't power up with the battery removed.
I thought I may have been able to track down this laptops schematics to test the currency through the motherboard (sorry don't know the technical terms).
The other thing I noticed was the connection from the RTC battery to the motherboard is dodgy. The positive wire wasn't snug into the white plastic doodad (again don't know the technical term & too tired to Google it ). I did fix it as best I could but it made no difference when I reassembled the laptop.

I'm not sure who replaced the hard drive. She was told it was new but it's dated 2013. Not sure if this is common practice. She's told me the other technician replaced the HDD as this is what he believed to be causing the BSOD.
I feel like I need to put in another motherboard to confirm our suspicions but she doesn't want to spend any more money. With any luck I'll score her laptop for payment and eventually have another tinker with it.
Thanks again.

 

The fact it does not work with the battery removed suggests it could the power supply, or some broken circuit inside the notebook after the power connector. If you have a multimeter, you might see if you have voltage past the notebook's power connector.

You might also try another power supply. I use and recommend a Automatic Universal 90W Notebook Power Adapter. I use this on service calls and when troubleshooting notebooks. You select the proper tip (out of 13 provided with this adapter) and it automatically adjusts its output voltage for the battery and notebook it encounters. Thus far, I have had no problems using it on my own Toshiba, as well as several clients’ Dells, HP/Compaq, eMachine, Sony, Lenovo, Acer, and even Apple notebooks.

 

I'll definitely look into purchasing the universal power adapter. Thank you. I probably should have mentioned in my original post I did try another genuine Sony PSU but still nothing.

As you mention, checking for a broken circuit, is what I want to do but a bit tricky for this learner. I do have a multimeter and have checked the voltage on the PSU, the connection to the dc jack and the connection to the motherboard. All were fine. I thought I would need the schematics to work out which "bits" on the motherboard I should use the multimeter on. I've not done that before so not sure which points to test.

Thank you again

 

Well, then I would not worry about the universal supply, unless that is just something you want to keep on hand.

Then you are pretty much out of luck. Years ago, detailed circuit diagrams/schematics were fairly easy to come by - but not today. Motherboards have become almost disposable items so generally it is just cheaper, in terms of labor, to simply replace the board than it is to troubleshoot, then replace the part. Troubleshooting could easily take an hour or more but swapping a board for someone experienced could be done probably 15 minutes. So makers don't bother to develop and publish schematics - if then even have any one who could read a schematic any more - let alone remove and solder in a replacement part without burning the board or frying the new part. Even for warranty returns with new systems, they just plug them into a test mock up and a computer reports what is wrong. If the labor and replacement parts cost more than the cost of new board and the labor to simply swap them out, they just replace the board.

 

And with the new board, all of the connections (power, USB, etc.) will be nice and snug.

 

I'll definitely purchase the universal adapter. How tragic I didn't think of one before.

I think I have to try and learn when to stop trying to fix a computer, something I find so hard to do. Due to my tenacity I have soldered a dc jack back onto a motherboard. Incredibly it's still running! That was about 2 years ago on a friend's laptop.

So I think in the end the motherboard in this laptop is fried. If only I could confirm it 100%. Like that annoying Frozen song "Let it go, let it go".

 

Gee, thanks for putting that in my head!

 

Just for you for all your help. Words included so you can sing along