Flashing LCD screen problem

[#1]

I have a largish, oldish desktop with a LCD screen (iiyami Prolite E2207WS).
It's recently got a tendency to flash white, but with a multitude of vertical multi-coloured lines every couple of seconds.
Reducing the size of displayed windows substantially tends to reduce the severity.
Graphics is a nvidia card which claims to be 512MB:-

Quote

01:00.0 VGA compatible controller: nVidia Corporation G71 [GeForce 7300 GS] (rev a1) (prog-if 00 [VGA controller]) Subsystem: Giga-byte Technology Device 342a Flags: bus master, fast devsel, latency 0, IRQ 18 Memory at d0000000 (32-bit, non-prefetchable) Memory at c0000000 (64-bit, prefetchable) Memory at d1000000 (64-bit, non-prefetchable) [virtual] Expansion ROM at d2000000 [disabled] Capabilities: [60] Power Management version 2 Capabilities: [68] MSI: Enable- Count=1/1 Maskable- 64bit+ Capabilities: [78] Express Endpoint, MSI 00 Capabilities: [100] Virtual Channel Capabilities: [128] Power Budgeting <?> Kernel driver in use: nvidia Kernel modules: nvidia_173, nvidia_current, nvidia_current_updates, nvidia_173_updates, nouveau, nvidiafb

Booting from the latest Ubuntu CD makes no difference.
Is this a card fault or a screen fault?

[#2]

My guess would be the screen,  but the usual trial of parts is required, just to be sure.
You could try switching the input  between VGA and DVI to see if it makes a difference.
Then try a different display  (another monitor or TV),  and if possible,  try the monitor on a different system.
That would usually be sufficient to determine which one of the two is at fault  (assuming they're not both failing!)

[#3]

What you describe is very similar to an issue I had on and off (excuse the pun) for some time with my llyama ProLite E2607WS.
Never did solve the issue as it was intermittent and only happened every few months. But I did find that taking out the HDMI cable from the back of the PC and plugging it back in resolved the issue each time. Since building my new PC in April this hasn't happened.
Strangely, I put my old MB, with graphics, CPU and RAM 'as is' into SWMBO's case and she has never reported the flickering issue at all.

[#4]

My issues were daily.
I haven't got a VGA cable. 
But I do have a screen with a DVI connection I can borrow.
Did a lot of borrowing and plugging/unplugging and the problem appeared to disappear.
However, when I plugged the original screen in (without switching the computer off),
the problem was still absent.
I'm betting it's not for long though. 
The question is:-
Does the problem lie with a dodgy DVI connection or with the screen itself.
If the latter, it means I can replace my 22" screen with a 24" screen. 

[#5]

No!
It's a new, slightly bigger, screen for me.