I have an HP also (a dv5224nr) but I have a
6 1/2 yr old Dell Inspiron 5000 that had the same problem. I would open the book, power it on and the screen sometimes turned white before the boot process had completed. At first, all I got was a screen streaked with really pale color then all went white after about 20 minutes of operation. I ran diagnostics - no problem. I thought it was the cable so I disassembled the machine to verify and pulled and re-inserted the cable - no problem there, symptom persisted. I thought it was heat - no problem there since the machine did it while still relatively cool. It was not the GPU or inverter since those would cause it to do it all the time. In your case, it sounds like it might be the LCD cable, but does the screen come back to normal if you leave the machine open and reboot? Will it come back if you suspend and re-awaken the machine? Sometimes from opening and closing the machine, the little conector pins recede into the plastic connector and you have to take the cable off to correct it by bending them a bit so they can't do that so easily. If the screen comes back to normal when you leave the machine open and re-boot or suspend it then re-awaken it, you should suspect a corrupt driver. This is what happened to me. I tore my hair out over the problem, even re-installing the ATI video driver 3 time to no avail. The problem? A hard drive that was so badly fragmented that the driver was corrupted no matter how many times I re-installed it!!! I de-fragged 4 times in a row and the problem disappeared. Try the simple stuff first before taking the machine apart. I know that sounds obvious, but I forgot that little piece of wisdom and wasted much time and effort. The first procedure if your problem is not with hardware is to defrag at least 3 times. That's the first and simplest method to try to repair a corrupt driver. Also try attaching the laptop to a good external monitor to see whether or not the video card is going to lunch. Good luck !!
