Mystery update: 😉

Well I just tried the FX5950 Ultra in a different mobo, an Abit KT7A. The RAM stick in this board is a different stick to the previous set up, and I removed the only other card from the other set up which was a basic soundcard. The CPU is different too. In fact the only thing which is being reused from the previous Gigabyte test mobo is the Corsair 450W PSU. ...And I get the same problem running Duke Nukem 3D - that is, strange graphical glitches seen on the screen. So, it's either the FX graphics card, the PSU, the nVidia drivers (77.72), or my messed up win98 HDD installation. Which one should I try changing first? 😀

Edit: I'm sorry that this thread has temporarily changed in to "what's wrong with my FX5950 gfx card?". I will remove this card soon, and retry the Radeon XT inside the "new" Abit testing mobo.

But quickly back to this FX card - I tried a few different nVidia drivers, and I still get a strange graphical glitch on Duke Nukem 3D, and also Shadow Warrior (another 3DRealms game), but this problem disappears if I chose to "restart in MS-DOS mode". So, I guess it's a driver glitch?

Edit 2: I DL'd the 61.76 nVidia drivers from the gigabyte website for the FX card, and when I run dxdiag.exe, it freezes on one of the D3D tests - the one with the bouncing white square in full screen mode.

Edit 3: I tried reinstalling DX9, and also the unofficial SP for win98. The full screen D3D test still freezes. Then I changed the PSU. Unfortunately, I've only got a spair 350W PSU, but it's a good one made by Nexus. But that D3D test still freezes. Then I changed the nVidia drivers again, to 71.84, but that D3D test still freezes. But then I fixed it - and the solution was really weird. The CD-ROM yellow ribbon cable was badly twisted. I threw it away, and replaced it with a boring grey one. And just by doing that, the D3D demo now works. Weird. But I'm still having problems with Duke Nukem 3D, but at least I solved the dxdiag problem.

You may need to use the NOLFB utility to run Duke3D/Shadow Warrior (Build engine games) under Win9x.

HunterZ wrote:

You may need to use the NOLFB utility to run Duke3D/Shadow Warrior (Build engine games) under Win9x.

Yes! Thanks very much, that worked! 😁

Edit: BTW, the temp on this FX5950 Ultra is just 33C, at desktop idle. Seems very low. The fan seems to work - and when there's plenty to do on screen, it gets faster, then slower again if you go back to the desktop. The power cable is plugged in OK. Perhaps this gfx just runs cool?

OK, I removed the FX5950 as it works. I then put the Radeon 9800 XT in to this different test Abit KT7A mobo with the different PSU, and I get the same problem as before - corruption of BIOS POST message, and also of the Windows 98 splash screen. This more or less confirms things: the ATI gfx card is broken.

I'm seeing some anecdotal evidence that the KT7A has compatibility issues with Radeons:
http://www.tomshardware.com/forum/135068-33-a … 00-gforce4-4000
http://www.gamingheaven.net/ati-graphic-cards … 800xt-prob.html

I don't think his problem is indicative of bus problems though. In my experience, that kind of corruption indicates something wrong with the video card's RAM.

If you wanna try something crazy RG100, try gently flexing the PCB of the video card a little while it's running. I had a vid card with some bad solder joints and doing this actually would fix it up briefly 🤣. Of course this might kill it more so "at your own risk"!!!

I thought the cure for bad solder joints was to bake it in the oven.

I baked a notebook GeForce 7900 and fixed just this kind of problem actually. 😜 But I also killed a GeForce FX 5950 with the same problem. I think you need to have a board with solid caps or they'll burst cuz the electrolytic caps have a much lower max temp. Actually I think Radeon 9800s use solid caps....