Hp dv9000 screen is dim can only see shadows works fine with external monitor. have replace dispay panel and inverter board still have same problem

i would off said inverter but if you have done it 3 times as long as its the right inverters its not that,not sure but i would check your onboard graphics,or a lose wire going to the inverter.
somthing does not sound right.

Is the display slightly visible? As in seeing shadows on the screen? You may need to replace the inverter board.

If you have replaced the LCM cable (the cable that connects the screen to the motherboard) and the screen and replacing the inverter board doesn't work then you have motherboard fault.

check the power source with a multimeter to make sure there's power from the systemboard to the inverter.

This might be a sign of a faulty LCD cable or screen inverter board.
The LCD cable transfers data signal from the motherboard & video card to the LCD screen. It also supplies high voltage DC power to the screen inverter board. The screen inverter board works as a power supply for the backlight lamp mounted inside the LCD screen. It converts low voltage DC power to high voltage AC power needed for the backlight lamp.

Test with an external monitor attached to the laptop. If you get display on the external monitor, then this confirms the case.

Have you tested it with an external monitor?

I would say you either have a damaged inverter board or screen baclight lamp. Usually the inverter board fails in one of the following ways:

1. When you turn on the laptop, the screen lights up for a short period of time and then goes dark. You still can see an image but it is very dark, almost invisible and definitely not usable. When you restart the laptop, the screen lights up and then goes dark again. The laptop works fine with an external monitor.
2. Your laptop turns on but the screen remains dark all the time. You still can see a very dim image outline. The laptop works fine with an external monitor.
3. The laptop screen works fine for hours or even days, but sometimes it goes very dark as it mentioned above. When you restart the laptop, the screen works fine again.

Inverter failure symptoms are very similar to backlight lamp failure symptoms and in most cases you cannot tell which one is causing the problem until you replace either the inverter board or the backlight lamp. From my personal experience, inverter boards fail more often than backlight lamps. If you have to guess, replace the inverter first.

Have you tested it with an external monitor?

I would say you either have a damaged inverter board or screen baclight lamp. Usually the inverter board fails in one of the following ways:

1. When you turn on the laptop, the screen lights up for a short period of time and then goes dark. You still can see an image but it is very dark, almost invisible and definitely not usable. When you restart the laptop, the screen lights up and then goes dark again. The laptop works fine with an external monitor.
2. Your laptop turns on but the screen remains dark all the time. You still can see a very dim image outline. The laptop works fine with an external monitor.
3. The laptop screen works fine for hours or even days, but sometimes it goes very dark as it mentioned above. When you restart the laptop, the screen works fine again.

Inverter failure symptoms are very similar to backlight lamp failure symptoms and in most cases you cannot tell which one is causing the problem until you replace either the inverter board or the backlight lamp. From my personal experience, inverter boards fail more often than backlight lamps. If you have to guess, replace the inverter first.

Quite often this is caused by someone changing the display type. There should be a function key control that allows you to view just your lcd display, an external display, or both. Try and change that setting and see if it will resolve your issue.

If you have replaced the screen and the inverter, about the only thing left is the flexible cable from the monitor to the video card. I take it that the Fn+F8 makes no difference?

You could have a faulty video card, or a faulty inverter, (this supplies high voltage to the CCFL lamp), or a faulty CCFL lamp.

Connect an external monitor to the laptop and power it up, if you see a clear image on an external monitor, this means your video card is OK.

If you see a very dim image or flicking image on the LCD screen it means you have a backlight problem.

Dim image and/or dark display on the laptop's LCD screen indicates a faulty LCD backlight and it could be the inverter that supplies high voltage to the CCFL lamp or it is the CCLF lamp is nearly burnt out or burnt out, most likely this is the case.
The inverter can be replaced easily but the CCLF lamp is more time consuming and requires soldering skills.
Check out www.lcdparts.net for parts, repair service and DIY info.

 Hello jarkk, I believe your problem is with your backlight inverter. the hard drive should be installed for this process of checking it on an external monitor. with the hard drive removed it will not boot to the operating system. with the drive in, use the external monitor. if the monitor works when plugged into the external monitor plug, this will eliminate a bad video card. if the screen is still black on the laptop screen, replace your backlight inverter. the last case cenario is to make sure your backlights are not burnt out.