Ti4200 broken?

I have a Ti4200 card which seems to have a major problem. It works fine when
displaying the desktop, but whenever it is called upon to display 3d (games)
the display either freezes immediately or sections of the graphics are not
displayed, with funny stripes where textures should be.

I have run DXdiag which reports no problem, reinstalled my Nvidia drivers,
reinstalled Direct X 9.0b and reinstalled my FPS games, all with no luck. I
have installed the Nvidia drivers which were rock solid previously, to no
avail.

I have physically reinstalled the graphics card and checked all my drivers
for errors, again with no luck. When I run 3DMark 2001 I either get no
display, or again immediately frozen graphics with corruption.

Is there any test I can do to find out if my card has bitten the dust? Any
benchmarking or software that will test my graphics card and tell me if
there are problems? I don't want to buy a new card to find I have the same
problems, but I have run out of solutions.

Is it possible for my desktop and day to day applications to display
correctly, even when my card has turned up its toes for games playing?

I have just run 3DMark right through and get the following results:-

1.Car drive - freezes or corrupted graphics
2.Dragon - freezes or corrupted graphics, apart from slow pan of the city
which is smooth.
3. Lobby - both freeze or miss graphics, but sideways running works
4.Nature - freezes or missing graphics
5.fill rate - single texturing - works
6.fill rate - multi texturing - works
7.High polygon count - works
8.High polygon count (8 lights) - works
9.Environment bump mapping - works
10.DOT 3 bump mapping - freezes
11.Vertex shader - works
12.Pixel shader - works
13.Advanced pixel shader - freezes
14.Point sprites - works

I get a 3DMark of 799 instead of my usual 7100. What I am asking is, is it
possible for a card to produce these results, yet still be physically
damaged, or am I still trying to locate a software fault?

Machine specs - AMD Duron 1.3, 1GB SDRAM, QDI Mobo K7V8363 Kinetiz 7B, 20GB
& 40gb HD, PNY GeForce 4 Ti4200. Windows XP Home Edition 2002 & SP 1, Direct
X 9.0b, Nvidia 53.03

Many thanks