When i turn on laptop screen goes all black no display

A) Shining a flashlight at the screen at various angles, do you see faint images?
No? Go on.

B) Laptop OFF, monitor OFF, connect a VGA monitor to the VGA port on the laptop.

Compaq Presario v3000? Left side towards the rear.
This is an example of a VGA connector (port), and VGA Cable,

http://en.wikipedia.org/wiki/VGA_Connector

Scroll down a little for VGA cable example. Note color of connectors does Not matter.

You can use a CRT type of monitor (Looks like a small TV ), or a flat LCD screen monitor if it has a VGA cable.

http://www.wisegeek.org/what-is-a-crt-monitor.htm

Turn the monitor on. If a CRT type allow it to warm up.
Turn the laptop on.
By factory default settings, the display should show on the external VGA monitor.

IF not;
There are at least 3 display options;
1) Internal display of laptop monitor ONLY.
2) Internal display of laptop monitor AND external VGA monitor.
3) External VGA monitor ONLY

Press, and hold down on the Fn key, and at the SAME time tap once on the F4 key.
The F4 key is the Display Toggle-Over key.

Still no display on external VGA monitor? (It takes a second)
Hold the Fn key down again, and tap once more on the F4 key.

NO display on the external VGA monitor, suggests a problem with the graphics chipset.
Most of the time it is the Mounting, of the graphics chipset TO motherboard.

The graphics chipset is mounted to the motherboard, with a BGA surface mount.
Ball Grid Array,

http://en.wikipedia.org/wiki/Ball_Grid_Array

Nvidia GeForce Go6150 graphics chipset,

http://www.ebay.com/itm/HP-COMPAQ-PRESARIO-V3000-V3200-LAPTOP-MOTHERBOARD-/390287984982?pt=Motherboards&hash=item5adefa0956

http://www.ebay.com/itm/1PCS-nVIDIA-Geforce-NF-G6150-N-A2-BGA-chip-north-bridge-Chipset-for-laptop-/190695516885?pt=LH_DefaultDomain_0&hash=item2c6656aad5

View an SMT/BGA Rework Station at work, and learn more about the Solder Balls, and BGA surface mount,

http://ersa.com/art-ir-pl-650-346-1472.html

Scroll down a little, and click on the Red -
Take a few minutes to view the IR 650 demo video.

http://www.youtube.com/watch?v=JEpnqhRYGLw

Uploader comment;
"HP Pavilion DV6000 Blank screen fix BGA rework video problem
This BGA rework fix also works on the HP DV2000, DV6000 and DV9000 there are a couple more HP's with this BGA video issue.
This is a design flaw that we solved with our upgraded copper heat sink and thermal compound.
Also effected by this issue are a couple Compaq models. The Comaq Presario V3000 V6000 and a couple of the Pavilion models."

Not showing for advertising of repair. Showing for adding extra copper sheeting material, to the graphics chipset.
A BGA Rework Station is the best method.

The problem, is inadequate cooling for the graphics chipset.
Bad design by HP.

As you can see in the above information, the bottom of the graphics chipset has Solder Balls.
These Solder Balls match up with Copper Pads on the motherboard.
(The Copper Pads are also gold plated)

The graphics chipset is set into place on the motherboard, with the Solder Balls lining up on the Copper Pads.
Heat is then applied at a specific temperature, and length of time.

This action melts the Solder Balls, and solders the graphics chipset TO the Copper Pads.
Which in turn of course, solders the graphics chipset TO the motherboard.

The solder connections made are called Solder Joints.
When the graphics chipset repeatedly overheats, the solder connections partially melt again.
Then the laptop is turned off, and the graphics chipset cools down.

This causes Cold Solder Joints, and a bad contact of graphics chipset TO motherboard.

If this is a problem with your laptop state back in a Comment.
Going on............

IF, the display shows on the external VGA monitor, and is good; the problem is the Video Cable, or inside the Display Assembly.
(screen Inverter or LCD screen)

Let me know after your diagnosis what the outcome is.
1) NO display on external VGA monitor.
2) Display on external VGA monitor.

Post back in a Comment.

Regards,
joecoolvette


Service Manual,

http://h10032.www1.hp.com/ctg/Manual/c01035667.pdf

(The above is a direct link to a PDF file.
The computer you are using now has Adobe Reader on it, which uses PDF files.

After you click on the link it may take up to 30 seconds, before the first page comes up.
The PDF file will not show until the file is fully downloaded.

IF the link does not work let me know in a Comment.
I will link you the HP Support page it came from )