VOGONS


First post, by T-Squared

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I was using one of my other video cards (an ATI All-in Wonder Turbo) for a while based on how reliable it was, but now I'm starting to question it.

It's most obvious when playing Doom for DOS, or the Boom sourceport.

The sprite representing the Doom Marine's hand shows missing pixels, several HUD sprites, and several textures in the level show flickering or noise within lines of particular pixels. (Not per-texture, where the texture is corrupted; but at the per-pixel level, where the rendered image has visual glitches.)

What makes this odd is that this visual corruption is always in the same place in the image.

It's not memory, is it? (Mach64 Diagnostics say the ICs are fine.)

Or is it a bad connection, based on age/bad GPU? (Yes, I understand these weren't exactly GPUs at the time, but bear with me.)

Reply 1 of 4, by Tetrium

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Would help if you can upload some pics of the display corruption.

Whats missing in your collections?
My retro rigs (old topic)
Interesting Vogons threads (links to Vogonswiki)
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Reply 2 of 4, by T-Squared

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Unfortunately, I can only give approximations at the moment. I'll try to get a picture later.

The one on the top is an approximation of what happens from the ATI Rage Pro Turbo.
The one on the bottom is from another ATI card (a Rage Pro PCI)

What I'm having trouble with is the Feature Connector. The image on the monitor is fine. It's only the image that comes from the pin header on the PCB that I'm having problems with, and I don't know what's wrong.

On one hand, I do have experience desoldering BGA (Ball-Grid Array) and QFP (Quad Flat Package) chips, so I'm reworking the Rage Pro Turbo to see if there's a faulty connection between the board and the chip.

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Reply 3 of 4, by T-Squared

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Ok, I may have slightly exaggerated the picture on the bottom in my previous post, but my memory sometimes isn't so good.

For the Rage Pro PCI, this is what each game looks like: https://imgur.com/a/uGSKt6c

Reply 4 of 4, by T-Squared

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Ok, checking with another card, I may have a solution.

I think the computer's power supply may be the problem, causing electrical noise on the power rails. I'm seeing low-quality capacitors within the supply.