Dead computer

  • Thread starter Thread starter Terry
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Terry

A friend of mine wants me to look at his daughter's laptop. He says
it won't even come on. I told them I would have a look at it, but if
it won't come on, I don't think there is anything I will be able to
do.

Where to start?
 
Terry said:
A friend of mine wants me to look at his daughter's laptop. He says
it won't even come on. I told them I would have a look at it, but if
it won't come on, I don't think there is anything I will be able to
do.

Where to start?
Click to expand...

Start with a description of the symptoms, from the owner.

You have two power sources (battery, adapter) and a
"black box" of electronics. If you don't intend opening
the unit up, then you listen to the description of the
symptoms leading up to the complete failure. If you
hear the right set of conditions, maybe the adapter
is bad, and then you find another one to test with.

Inside the laptop, there is going to be a chunk of circuitry
that handles battery charging, conversion to motherboard voltage
levels, that sort of thing. But without a schematic, it
would be pretty tough to know what you're looking at. Most
engineers and layout people, would not waste their time
labeling anything in a useful way.

I have the same kind of problem here. My stereo died, I opened
it up, and it has a whole bunch of little subassemblies. The layout
is not orderly enough to even say "this part is power", "this part is
preamp", it is just all plunked down on the main circuit board. I found
a datasheet for the main amp (a module with heatsink), so at least I know
it uses a pretty high DC voltage (and the amp part is still working). But
the mixer died, and that part is just a mess. I still haven't decided
where to start, because I really don't want to unscrew anything (no place
to lay it down while working on it, short assembly cables etc).

Paul
 
Terry said:
A friend of mine wants me to look at his daughter's laptop. He says
it won't even come on. I told them I would have a look at it, but if
it won't come on, I don't think there is anything I will be able to
do.

Where to start?
Click to expand...

It could be many things, but many laptops will not function if the
battery is bad. If another can be tried, that is the first thing I
would do. How old is the computer/battery?
 
A friend of mine wants me to look at his daughter's laptop. He says
it won't even come on. I told them I would have a look at it, but if
it won't come on, I don't think there is anything I will be able to
do.
Where to start?
Click to expand...

Measure battery voltage. If battery voltage is about what its label
reads (maybe 13 volts?) then laptop has at least one good power source
and still will not work.

Another suggested shotgunning - replacing parts until something
works. Laptop batteries are expensive. Smarter is to first learn
what is and is not working.

Same meter to measure a battery will also measure voltage from
laptop's power brick. A dead battery and a good power brick again
means the problem is inside that black box called a laptop. Measuring
is simple - significantly less expensive than shotgunning until
something works.
 
I was presented with the same problem.
The battery was dead, and the AC power brick was
also dead. I bought a replacement power brick from
China, for $24 including shipping!, and that was
all there was to putting it back in service.

A second laptop found it's way to me, this time from
a neighbor, and it was the same story. So I'd measure
the voltage out of the power brick first.

I know some laptops don't require the battery to be
installed. I used two of them that way for years and years.

Mike
 
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