Aspire 9420 - Help required!

Ok, I will try to keep this brief, but please respond with questions if you need more detail in order to help me.

I have had my Acer Aspire 9420 for a couple of years now I think and it's been pretty good up until now, no real problems. Then out of the blue the other night, while watching some streaming video online, the screen just went black and I couldn't get it to come back. It was as if the battery had died (although it was plugged in at the time) and I had to use the power button to do a hard shutdown.

When I then rebooted, I got one of two behaviours:

- The BIOS and Acer splash screen appeared, but with lines of various colours down them, or other artefacts on the screen, before it tried to boot into windows and then after the Windows loading screen either BSODed on me (very fast so I couldn't read it) or just left me with a blank screen and no response to any keypresses, as well as no HDD activity, resulting in me having no option but to hard shutdown again.

OR

- It started up, but with patches of black and white on the screen which slowly alternated, as if the screen had been smacked or something. Very hard to describe, but it basically slowly pulsed from black to white and back again repeatedly, with patches of varying greyscale on the screen, also indefinitely and until I hard shutdown again.


Since leaving it overnight, I can now get it as far as getting just past the Windows splash/loading screen, either via the Startup Repair or the menu regarding whether I want to go into Safe Mode etc. Which I get depends on from what scenario it was last shutdown it seems. In all of the above scenarios, there is another strange visual behaviour on the screen, which is that the bottom 10-15% of the screen is a replication of the top 10-15%, which is very strange (i.e. when I'm in the Startup Repair - which displays without any other visual artefacts btw - if I move the mouse cursor to the top of the screen, it also shows at the bottom, hopefully that makes sense).

So anyway, regardless of whether I go in via any of the Safe Mode options, Startup Repair, or anything else it presents me with, I can never get it to boot any further than the windows loading screen, does anyone have any ideas? I did give in to temptation earlier and opened it up, re-seated the RAM and HDD and made sure everything seemed ok - no loose screws rattling around or anything on fire, lol.

I have been running the Windows 7 RC on this machine for a few months, so while it might be relevant to the troubleshooting of the problem, I don't believe it's the cause, as it's been fine up until now.

Any help would be greatly appreciated, as I really don't want to lose my lappy, or have to pay a bundle for someone else to fix it up for me!

Thanks in advance, any questions, please fire away!