Hello,
I have an Elitebook 8730w laptop with Dreamcolor RGB LED display and nvidia quadro fx 2700m display adapter.
Until last week, I was able to control brightness to a reasonable level as per ambient light. Sometimes the controls would stop working, but a reboot usually fixed that.
Last week as I was working we had a huge power failure that lasted a couple of days, with lots of fallen trees in our area. When the power came back on I noticed the screen was very dim (although legible in a dark room).
I have tried:
- turning the ambient light sensor off and on and using a flashlight to force a change
- adjusting the brightness using the sliders in Power Options
- going in safe mode and adjusting brightness from there
- reloading previous good configurations all the way back to 2010
- removing the battery and pressing the power button for 30 seconds
- removing the battery and letting the computer sit without the battery overnight
- changing the display adapter driver (windows tells me I have the latest)
- removing the monitor and display adapter. Brightness still cannot be changed with generic driver
- uninstalling and updating the HP Display Assistant
- updating the BIOS
- replacing the power supply with a spare
Nothing has worked.
When this happened early in my attempts, during starting, for a few minutes I had the screen flash blue and red, from POST all the way to windows, which makes me believe something went wrong either firmware or hardware, but it stopped after a few minutes and back to the dim screen.
I have searched on this site and elsewhere and none of the 10 or so solutions I have looked at worked.
I need to find out if it's hardware and whether I can repair this. Replacing a video card or a screen is not a big deal for me, but replacing the motherboard is.
I wonder how this could have happened, considering laptops are powered with AC adapters that should stop all transients.
My questions to the experts are:
- Is there hope this is just a firmware/software issue? When I put the computer to sleep and when I bring the screen back on, for a fraction of a second (1/10 second or less) it feels like the screen goes to full brightness but immediately goes back to 0%.
- In HP Mobile Display Assistant, when checking the color after a fresh start of the Assistant, for a fraction of a second before the display is recognized as the HP Dreamcolor, I can see the brightness slider set at 50% (my standard for working indoors, but it immediately drops to 0% and grays out.
- Using the video card controls does change the display a bit, but not the actual brightness.
If its'a hardware issue, how can I determine what is wrong? The HP Support Assistant says there are no problems, and when I force a new scan it just stands there, with nothing happening for hours.
As you can see, it's not that I haven't done my homework. I've been on this since yesterday and it's driving me nuts, I just started to use this machine that was until recently my backup, only 6 months ago.
Thank you in advance for your help!
