what kind of cable do I need to use one laptop as the screen for another?

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My backlight went out on one of my laptops and I'd like to hook it up
to another laptop screen, what is the cable I need called?

Re: what kind of cable do I need to use one laptop as the screen for another?

Joe wrote:
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And when you looked in the user manual for the laptops, what
section told you that a laptop has a video input connection
for another laptop to drive ? It doesn't work that way. The laptop
screen is connected via a thin ribbon cable, to the motherboard
of the laptop. That is an internal cable, and the panels may
not have the same resolution, BPP, signal rates, or signal

If the laptop has a VGA output port on the back, you can connect a monitor
to that. For example, you'd shop at the store for an LCD monitor
with VGA input connector (as it is unlikely the laptop has DVI
on the back). Or a CRT monitor with VGA input. Then, a VGA cable
would complete the connection. You would also have to hope, that
there is an easy thing, like a function key to press, to get the
VGA output enabled on the laptop. On some desktop video cards,
enabling an output may require opening the display control panel,
which is hard to do if the primary display is no longer visible.
So before buying a monitor with VGA interface, check the laptop
manual, for a function key combo that enables VGA.

Another way to gain access to the laptop, would be with Remote Desktop
and a crossover Ethernet cable. Connect one laptop to the other. As
long as Remote Desktop is enabled, you can view what would have been
on the dead laptop's screen. So a second laptop running Remote Desktop,
logs into the laptop with the dead screen, and then you can see what would
have been on the other laptop's screen.


Neither solution comes with guarantees, if you are having trouble getting
the alternate solution going. (In other words, it is possible a step would be
required, where you'd need to be able to see the screen, to complete the
configuration steps.)

If you need the files off the laptop hard drive, the easiest way to do
that is to pick up a 2.5" USB hard drive enclosure, or a 2.5" hard drive
to USB adapter kit. That would allow access to hard drive files, if you
removed the hard drive from the broken laptop, and connected it to
an enclosure or adapter kit. Plugging the USB cable from the enclosure,
into another computer, would then give you access to the files on the
hard drive.

In terms of what is broken, there are several possibilities:

1) The CCFL lamp could be dead. But if that were the case, there would have
    been a prolonged period, where the screen was becoming dim, and the
    color of the CCFL light might be yellowish or off-color. So chances are,
    the lamp itself is OK. Not too many people report symptoms consistent
    with lamp failure.
2) There is an inverter module, that powers the CCFL lamp. The CCFL lamp runs
    at 700 to 1000VAC, at a high frequency. The inverter runs off 12VDC or
    thereabouts. If the connections to the inverter were bad, that might
    cause the problem. Sometimes, people find that unplugging and replugging
    the cabling on inverters or lamps, fixes things. (Requires access to the
    insides of the display on the laptop.)
3) There could be a short, between the high voltage, and an adjacent ground,
    where it feeds the lamp. Dust or moisture, or previous fiddling with the
    foil in the display area, might increase the odds something like that
    might happen.
4) If the lamp comes on for a second, and then goes off, there is one thing
    you can try. You can use the brightness adjustment, to decrease the
    brightness setting. Sometimes, that reduces the load enough on the
    inverter enough, to keep it running. Some people manage to squeeze a few
    more weeks operation from the laptop, before the inverter refuses to come
    on at all. Enough time, to back up the data on the drive etc.

On the Internet, you can find web sites that have "disassembly" pictures and
instructions. That might give a rough idea, how to get the thing apart. But
before I did that, I'd want the data from the hard drive, to be secured and
copied somewhere safe. In case the laptop never runs again...

Also, there are web sites that sell replacement inverter modules and CCFL
lamps. The parts sold, will not necessarily be exact replacements. In which
case, you may fix the problem, only to have a problem six months from
now. To some extent, the characteristics of lamp and inverter have to match,
and it is not clear to me how you guarantee they're even close.

Good luck,

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