Your description sounds like the power inverter. If you use the computer without going online, does it behave like this or does this only happen when you're on the internet?
BTW, an inverter is pretty cheap and relatively easy to replace, so if that's the problem, consider yourself fortunate.
I posted about this a few months ago and thought I had bookmarked/saved the topic but I guess I didn't.
I have a Dell Inspirion 1500 and it was running perfectly since the last incident and yesterday it happened again.
Everything loads in perfectly and it allows you to get as far as getting online, thought this morning it only loaded Windows XP and then this black screen appears. I've shut it down a few times and it would go load perfectly, get online and stay on for a few hours then suddenly the black screen would appear again.
This black screen is sheer...you can see the website that your on thru it...almost like a curtain.
For the life of me I can't remember what the tech told me was wrong and how I fixed it. Like I said, its been running perfectly for months.
Any help would be appreciated.

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