View Full Version : Laptop video problem

16-01-2012, 10:21 AM
I have an HP Compaq Presario 2500, its about 8 years old.

Often when I switch it on I can see a faint image on the screen, however it is not bright enough to use.
On other occasions it is perfectly fine on and stays that until I switch it off.

I feel that it starts fine on some occasions if the screen opened to just under verticle.

Any thoughts any one ? I don't mind opening it up to check anything that someone might suggest, as if
it continues to fault, it will be disposed of.

16-01-2012, 10:53 AM
Sounds like the inverter (produces high voltage for the LCD backlight) is not starting. Hard to say why, though.

Good luck.

16-01-2012, 03:46 PM
Hi Linw, just a couple of ?'s.
When the laptop starts with a good screen, if I then need to
adjust the angle of the screen, the video cuts out. Could this suggest
a short of some sort ?

Is the inverter located in the screen its self? What might it look like?

I have nothing to loose, so I might as well have a little looksee, I might
just learn something <grin>

16-01-2012, 04:45 PM
Laptops have a cable (maybe even sometimes two separate cables for some models) which run from the motherboard and sends video signals and power to the LCD and power to the inverter.

The problem is that they must pass through the laptop screen hinge and as a result of the screen being opened and shut many times the cables come under stress, and can fail.

If changing the angle of the screen can cause the problem it is quite likely that cable which is faulty in some way.

However, I can see how other cabling faults (such as CCFL cable) or bad solder joints on the inverter is a possibility with the same effect, but I would suspect the main cable first.

You can find cables on eBay such as: http://www.ebay.com/itm/HP-COMPAQ-PRESARIO-2500-LCD-screen-cable-DDKT3DLC000-CRC-/150706176728?pt=UK_Computing_LaptopAccess_RL&hash=item2316c9c2d8

Note there are many variations of the Compaq Presario 2500 so you would need to check your cable model number specifically if trying to get a replacement.