Laptop with dead motherboard

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I have a Dell Inspiron 8600 laptop, that I bought almost 1.5 years ago
- and I cannot power it on - either from the battery or an external
supply. I think the powersupply regulator on it's motherboard burn-out
in a power surge recently. At least I think that's what the problem is.

 I showed it to a laptop repair guy and he told me he couldn't identify
the cause, and that I should change the mother board ($500) - because
even if a particular IC has burned out - the whole mother board needs
be changed. I think this is a ridiculous proposition

I just wanted to ask you guys what are my options here ?

1. Do I really need to replace the motherboard ? How can I identify and
fix the problem. I don't want to show it to another laptop repair firm,
because they charge upwards of $30 to just look at the damn thing.

2. If I do need to replace the m/b, is it that expensive ?

3. If I choose not to go ahead with the replacement, what can I do with
my laptop. Essentially, it has a very good LCD (uwxga -1920 x 1080 )
and gfx card (nVidia6800). Also, it has 1GB memory.  Can I salvage and
reuse any of this in my desktop.
I was looking around the Net about using a laptop LCD as a desktop
monitor and it seems like a fairly involved project - and my circuitry
skills aren't that good.

4. Or can I sell the laptop off ? Where ? Would I get a good price for
it ?


Re: Laptop with dead motherboard wrote:

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The short answer is yes. There is no component-level service
information available for laptops (not even to service centers). All
repairs are done at the subassembly level only. At standard labor rates
of $65 to $100 per hour, the reverse-engineering required to perform a
component-level fix is going to be more than the price of a new board.
And parts might not even be available. Many of these parts are
unlabeled, or labeled with house numbers, and more or less impossible
to buy off the shelf.

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If you buy an OEM new part, yes.

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None of these parts are directly usable in your desktop machine with
the exception of the hard disk. Building a controller card to use the
LCD as a general-purpose display will cost close to or even more than
the price of repairs.

Your best options are:

1. Sell the pieces on eBay and use the money to finance a new laptop.

2. Look for an identical or similar machine on eBay that is
nonfunctional because of missing hard disk, broken LCD, etc, and
salvage parts from it.

#1 is much lower risk and likely to be the better longterm value.

Re: Laptop with dead motherboard

First, it's not terribly likely that your diagnosis is exactly correct.
  The external power supply (the AC adapter) is a switch mode switching
power supply, and they do a fantastically good job of stopping power
line surges from getting through to the equipment.

But if there was a power line surge, you computer could have gotten
zapped by a connection to another piece of equipment (printer, router,
phone line) not through the power line, but through a signal line.
That's more likely, in this case, than a direct power line hit, because
of the degree of isolation provided by the external AC adapter.

[By the way, have you checked the external AC adapter ... they are
pretty good at protecting their own loads from surges, but sometimes the
protection involves the power supply itself "taking one for the team".]

But ....

As to the comment made by the technician, "he couldn't identify the
cause, and that I should change the mother board ($500) - because even
if a particular IC has burned out - the whole mother board needs
be changed. I think this is a ridiculous proposition"

You may think it's ridiculous, but he's pretty much right on once you
eliminate everything else and are pretty much left with the conclusion
that it's the motherboard (I'm not saying you are there yet, but you may
be close).

If there is ANY problem on the motherboard, even just a blown fuse, the
only practical way that you are going to get it fixed is to completely
replace the motherboard.  And $500 is very typical for a motherboard
replacement.  That's why laptops are one of the relatively few products
on which an extended warranty can be a wise choice.

If you don't want to replace the motherboard, you can sell the laptop on
E-Bay for parts.  You will probably get as much as a couple hundred
dollars for it (I'm not certain of the specs of that model).  None of
the parts are salvageable for a desktop, but the hard drive, memory,
battery (if it's good), keyboard, optical drive, LCD screen, power
supply (if it's working) and even the CPU may well be salable.

At this point, the first thing to do is to verify that the problem is
probably the motherboard.  First, you need to verify that the AC power
supply is working.  Also, tell us exactly what happens when you try to
power up ... every nitty-gritty detail of what does and does not happen.
  Try removing and reinstalling memory.  Try only one memory module ....
then try the other memory module (only).  Try removing the hard drive
and seeing what happens.  The first step is to try to narrow down the
problem so that the only thing left is pretty much the motherboard. wrote:
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Re: Laptop with dead motherboard

Barry Watzman wrote:
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I tested my laptop with a couple of different AC adapters and my
adaptor on other laptops. No probems with the adaptor. The laptop
technician too elminated that as a problem. Also, the battery is still
in good condition - I tested it on another laptop.

However one interesting observation is that when I would connect any
(Dell) adaptor to my laptop, the green light on it would stop glowing.
I would need to disconnect the adaptor from the electrical outlet and
keep it disconnected for a couple of minutes. Then it would start
working fine again.

This led me to conclude that there was some kind of short in the power
supply on the motherboard and the AC adaptor was preemptively switching
off under the increased load.

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Should I sell the laptop whole or as parts ?

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Well - the nitty gritty detail is simple ;)  - with or without a
confirmed working AC adaptor - with or without a confirmed working
battery - if i press the power-on button I get *absolutely no*
response. There is  no indication as if anything at all is happening -
no whirring, no sound, no lights blink, the ethernet light doesn't
flicker, my mobile USB HDD doesn't power up. Nothing.

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I tried it. I also tried removing the gfx card and disconnecting the
lcd and keyboard. Same response. No response ;)

Re: Laptop with dead motherboard

  Barry Watzman has provided a short list of possbile failure reasons.
With information provided, number of possibilities would appear
endless.  Summary from your laptop tech does not provide useful
information.  Is laptop motherboard even provided voltages taht are in
spec?  Without even that first information, then no one can suggest a
useful solution.

  Barry has provided ideas to collect useful facts.  One more.  Measure
voltage on the laptop battery.  If that battery voltage is about or
above listed voltage, then problem is inside laptop and you have no
more hardware repair options other than shop service.

  But then that laptop serviceman should have already performed that
battery measeurement.

  Documents to get inside and better understand your Inspiron 8600: wrote:
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Re: Laptop with dead motherboard

the price on the motherboard new is 375.00 so 500 is in the ball park.
If the board is toast I would purchase a new machine with a core2duo
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Re: Laptop with dead motherboard wrote:
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I buy dead laptops for a buck or so.

When you run out of options, wash the motherboard.
Read the above line one more time "WHEN YOU RUN OUT OF OPTIONS"
you've got nothing to lose.  Try the other suggestions in this thread first.

Pull the motherboard. Take a toothbrush and Simple green to it.
It's like flossing your teeth.  You want to get the gunk from between
all those little surface mount leads.  Don't be shy.
Rinse in hot water...rinse it again...and again...
Blow dry with compressed air.
Take a toothbrush and isopropyl alcohol to it.
Rinse, rinse, rinse in  hot water.
Blow dry, blow dry some wanna get the water out from under
all the surface mount chips.  Gotta use compressed air.

Do this when humidity is high.  Use antistatic precautions.

I know it's tempting to skip a step.  Don't!  You can get simple green
at any grocery store on the planet.  If you don't have an air
compressor, borrow one.  Take your time blowing at an angle around EVERY
chip to force the fluid out from under.  It's not unusual for me to take
half an hour on the last blow dry.

Preheat the oven to the point that you can still touch the side without
seriously burning yourself.  Turn off the oven and put in the board for
half an hour.  Take out the board, reheat the oven, turn it off, put
back the board for another half hour.  Last thing you want is to bump
the thermostat and melt your board.

I've fixed several laptops that way.

Coke, coffee, water get dripped on it.
Stuff gets sucked in there...harispray, cigarette smoke, scented oil
candles, chimney smoke, cooking name it.  I've never had
this problem with a fanless system.
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