Zepto with screen flicker

Hello all,
I'm having a problem with my Zepto laptop 6625WD.
Here in start of december my Nvidia 8600GT 512MB GFX died, and I found a replacement. Happy to finally see color on the screen again when I inserted the card at the guy I bought it from, I failed to boot the laptop before I went home. When I came home it seemed that the screen flickered from full brightness (normal image) to dim lit lighting, where the image of the screen is watchable in strong lighting.

The funny thing is, that the flickering is in sync with my harddisk load frequencies. So, when my harddisk is loading up a program or having other activities, the screen goes totally black and I hear some hissing sounds from the buttom at the screen (my first guess was that the inverter has gone bad)
Small burst activities makes small flickers which is unbearable!
When there's no activity on the harddrive, there's no problem with the image - it views as it should.

This problem is present even when the bios is booting including when the load screen is present during the bootup of windows XP, which is the operating system of my machine.

I've tried to plug in an external screen and this works without a hitch, so it can't be the GFX and this makes me more or less clueless of what to do.

Of all the forums I've read, none has mentioned that the screen flickeringing is in sync with harddisk activity, which I think is pretty odd and more or less makes my incident quite unique I think - that's why I'm consulting you guys

What do you guys think is wrong with the display?

Really looking forwards to your insight!

Thanks alot for your promt reply!

So is it the bulb which needs replacement? Is it possible to replace it on my own?

The cables has been triple checked, so it cannot be them :-)

Thanks alot for your insight! I'll take a look at it - is there a serial number on the actual light inside the screen? Since Zepto has a Toshiba chassis it is very difficult for me to know exactly which light would fit with my LCD.

I'll post what I can if I try it out!

Before buying this light - do any of you know what might cause this problem? It could be nice to know for future reference :-)
It is just that I'm concerned of beginning to tamper with the LCD screen, and one can't be too careful about this sort of thing.

Could it be that there is some grounding which has been foiled when I opened up the laptop screen? Or could it be that the version of the GFX I got was a v1.1 when my old one was v1.0? Could it be because that this new GFX uses some other power options than the old GFX I had?

Problem fixed

I solved the problem. It seemed to be the plug from the reed sensor was not properly attached to its socket on the motherboard