I will tell the whole story of the problem, please excuse my long windedness, but I know how important details are in diagnosing PC problems.
My Wife’s HP Pavillion dv5-1004nr came with Vista 64, but I upgraded it to Windows 7 home pro 64 with no problems. Link to the lappy for (http://reviews.cnet.com/laptops/hp-pavilion-dv5-1004nr/1707-3121_7-33088546.html)
It was sent in once while still under warranty to have the thermal bonding on the CPU replaced, b/c of overheating. Over heating was fixed then.
About two months ago it began to have screen problems. The whites on the screen took on a flickering blue tint. When plugged into an external monitor there was no problem with color on the external (the problem still persisted on the main monitor).
I installed new video and monitor drivers with no change. I installed new bios with no change.
I did some research and concluded it was likely the internal cable that connects the motherboard to the monitor (whatever that thing is called). I never got around to replacing it.
The problem persisted, and got worse. The screen began to occasionally flicker white, for maybe 2 seconds at a time. Then finally after the recent Windows 7 updates (on 4-14-10 I believe) the screens began going solid black about a minute after start-up. The rest of the laptop seemed to be functioning fine. I transferred a bunch of flies off if it while it had the black screen. There was no cursor icon at this time. I should say that when the screen goes black it happens on both monitors. Which I found odd because the discoloration only effects the internal monitor.
I booted in safe mode, which seemed to keep it from going black, and my wife restored to the last restore point. After that it failed to boot completely. You could see the windows logo, but then only have a black screen with a white cursor (which I could move). It would not respond to control alt delete, or any other commands. Booting in safe mode and in low res mode did not help.
So here is where it gets weird. I put in an Ubuntu 64x disk and run it in live mode. The screen worked perfectly, as did everything else. There was no color problem with Ubuntu, at first. For about 4 hours the colors were fine, then the blue tint returned.
Then I restored the PC using a system image I created from January right after Win 7 install. Again the screen worked perfectly for about 4-6 hours. Then the blue appeared again. Now it has begun to flicker white.
I was convinced it was a hardware problem, and still am. But I am puzzled that changing OS seemed to delay the problem from showing up. Not sure why that would be.
Anyway, any help or advice would be appreciated.

Other Details:
We use Avast, it is updated, but it has not found any viruses. I doubt it is a virus issue anyway considering system image was from January, and Ubuntu had similar issues.
I have run several tests on RAM and Hard Drive, they are fine.
I have gone through the process of clearing static, removing battery and so on.
My fear is it is the MOBO, but I am unsure how to test this.
Thing is about 1 month out of warranty, I hate HP.

If the problem persists on the laptop's monitor and not on an external one then it might be the monitor itself. My dad's laptop had the same problem going on with it and once the laptop died to an unrelated issue ( he spilled a drink on it and basically fried the MOBO...all the while thinking I could just *magically* raise it from the dead...yeah right..) I took a look at the cable connecting the monitor to the MOBO and nothing seemed either out of place, burnt, or loose.
I would, however, try and replace that cable but be warned that it takes a LOT to get to it and change it. Be prepared to catalogue screws and where they go.

Well the black screen problem effects the external monitor as well as the internal one. It seems unlikely that a problem with the internal monitor would do that, same for the cable. I could be wrong though.

It sounds like the black and blue-tint issues are separate. "Black" sounds software related, while "blue" seems to be a hardware problem (screen cable not completely connected, or something with the screen itself). "Black" could be something with the graphics card as well but that's less likely.

If it's out of warranty, just take it apart and fiddle with cables for a bit, might help.

By that definition I'd say that it's overheating and that's what's causing all the problems and it also explains the delay.

Usually when there are problems after certain amount of time, they are HEAT related...
Also, you better not get another HP. Since the joining of Compaq, both brands have become worse and worse every month.

Hehe, my dad's lappy was ALSO an HP that started having monitor problems...

Yeah for future reference, avoid HP and Packard Bell laptops, computers and printers. My experience with them and their support has been nothing but grief.
Toshiba do good laptops.

Thanks Alias,
The laptop is not currently overheating, but it seems likely that the chronic over heating it had for a few months may have destroyed the cable, like you experienced.
Those cables are hard to find, I found one online for about $60.
When I open it up, I will look for the GPU heatsink problem you mentioned. I had heard of that before.
The forum you linked to is really interesting. From a cursory look it seems like they are dealing with HPs with Nvida gpus, mine is running ATI Radeon HD 3200. Still, that does not mean I don't have the same problem. It may be worth it for me to try the same tactics those folks are trying to pressure HP into repairing the lappy.
Again, I hate HP.