3dfx Voodoo5 glitches

[Justin1091]

Hello all,

For a few weeks I've been trying to fix a voodoo5 5500 agp video card. The machine locks up when running a 3d application in dual chip mode. I found out that it happens when a driver feature called 'guardband clipping' is enabled. This means that it can run in dual chip mode and that probably the chips are fine. By chips I mean GPU's.

I've been working with someone over at vogons.org trying to fix the card. Per his recommendation I have replaced all the capacitors on the card. This didn't work. I have another, working voodoo5 which I can use to compare voltages etc.

Other than asking for tips on what else to try, I have a question. Both cards have a couple of different resistors on them. Why could this be? Images on the internet of the card show the same resistors as on the good card.

I measured the voltages on the cards and the bad one reads 2.8 to 3.3v (the chips use
3.3v) and the good cards show 3.0v to 3.3v. That's what the power section reads. It takes 5v and 12v from a molex connector and changes it to 3.3v. 4 ics on the board do this.

I replaced a suspect resistor on the bad card and the power section now reads 2.6v to 3.3v. After this I have no idea how to proceed.

So, could the problem be in the different resistors the bad card uses? Or replacing the resistor was something stupid? Any suggestions on how to proceed?

No idea if this forum is the right one for asking a question like this, who knows

Thanks in advance!
Justin

[Sparkey55]

Re: 3dfx Voodoo5 glitches

Please attach clear high resolution photos of the bad card both front and back showing all your reworked areas. can you give us some background history of this card? Does it still have the 2 heatsink/fans attached? What exactly are the system specs in hardware in your setup? have you tested the card using official 3DFX drivers? What PSU are you using? Motherboard?

[Justin1091]

Re: 3dfx Voodoo5 glitches

Will post pictures tommorow. As for your questions:

The card has been in my possession for a couple of years, maybe 8. I got it off eBay and it never worked properly. Back then I used it for some time before getting another card in order to verify if it was indeed not working properly. So, the good card worked fine and I put this one away.

So now I decided to try fix it. The card has both original heatsinks+fans on them. I have tested the card in a Pentium II 233 machine (some 1998 gigabyte motherboard) and in a Pentium III 800 machine (Asus Cuv4-x) Tested under DOS, Windows 98 and Windows 2000. Used both 3dfx WHQL drivers, beta drivers and 3rd party drivers. Tried 4 different psus.

Also compared it to the good card. Like this: put in bad card, run game = freeze. Change nothing and put in good card, run game = ok. The one option (that i know off) that makes it freeze is guardband clipping.

[Per Hansson]

Re: 3dfx Voodoo5 glitches

AFAIK Guardband clipping is just to offload rendering of unseen (not visible) scenery.
Thus offloading the CPU with resulting higher FPS, don't think that has anything with SLI to do.

As for the differences in the cards they are probably of different revisions?
There should be a revision stamped somewhere on the cards.
Edit: attached pictures shamelessly stolen off ebay showing revision numbers 2100, 2300 & 2500

[Justin1091]

Re: 3dfx Voodoo5 glitches

Ah, I looked at the front of the card and saw REV A. on both boards. Bad card is REV 2300. Good card is REV 2100. I think I should put the old resistor back then (it didn't have a number on it only a blue color). I put a new resistor on it with the value of the good card. Guess you probably can't use other cards with different revisions for parts.

About guardband clipping you are correct yes, strange that it freezes when it's enabled.

Edit: guardband clipping does work in single chip mode on the bad card though.

[Justin1091]

Re: 3dfx Voodoo5 glitches

Hmm, 2100, 2300 or 2500 might refer to the week it was produced. E.g. week 25 of 2000. If that's the case the difference in resistors between the boards is still not explained. Could still be revision numbers though.

[Per Hansson]

Re: 3dfx Voodoo5 glitches

They are revision numbers.
Nobody would spin a new PCB design each week!

[brethin]

Re: 3dfx Voodoo5 glitches

You need to provide clear high resolution pictures of the card so people can help you.

[Justin1091]

Re: 3dfx Voodoo5 glitches

Here are some pictures before replacing the caps. https://imgur.com/a/9ovsLMo
Notice c90 is wrong, this was a stupid move by me, spotted by someone at vogons.org I have since then replaced it with the correct one.
I can post new pictures tomorrow.

What I was talking about earlier is R112.

In case someone is interested in the vogons topic: https://www.vogons.org/viewtopic.php...a4ac37b0377da0

Guy there really helped me, unfortunately he isn't responding for some time.

[Sparkey55]

Re: 3dfx Voodoo5 glitches

Have you turned off Hidden Surface Removal?

[Sparkey55]

Re: 3dfx Voodoo5 glitches

I did read one of your posts on another forum that you sprayed an AGP slot with contact cleaner. What exactly was it?

[Justin1091]

Re: 3dfx Voodoo5 glitches

I can try turning that off, I'll need to install a beta driver. I'm 99% sure it's disabled in the 3dfx reference drivers.

About the contact cleaner no idea, must be a long time ago. Quite useless action as well, and probably unsafe. This is my second attempt at the card. Must have been non lubricating (or however you call it in English - not for switches, pot meters etc.). Has to have been on the current motherboard I use since I never got another one.

[Sparkey55]

Re: 3dfx Voodoo5 glitches

I can try turning that off, I'll need to install a beta driver. I'm 99% sure it's disabled in the 3dfx reference drivers.

About the contact cleaner no idea, must be a long time ago. Quite useless action as well, and probably unsafe. This is my second attempt at the card. Must have been non lubricating (or however you call it in English - not for switches, pot meters etc.). Has to have been on the current motherboard I use since I never got another one.

If the cleaner was anything like WD-40 that is the wrong kind of cleaner and is electrically conductive. Do not use anything containing Silicone.

[Justin1091]

Re: 3dfx Voodoo5 glitches

If the cleaner was anything like WD-40 that is the wrong kind of cleaner and is electrically conductive. Do not use anything containing Silicone.

No, it wasn't like WD40. Think it was a spray obtained from an electronics store specifically to be used for cleaning corrosion and dirt. I don't remember the specific can used. Thanks for the tip though! I wouldn't use it again on a PC anyway, well except for switches on the pc case. I'm 100% sure the problem lies with the card, not the motherboard. Anyway, the motherboard's slot is fine and HSR is disabled per default on the old 3dfx reference drivers.
According to this webpage, you need to enable it with a registry variable:
https://www.anandtech.com/show/683/13
I used every driver available to test it, including 1.00.01 (may 2000). That driver doesn't support HSR if I'm correct.

Did you see anything worth looking into on the photographs?

[Sparkey55]

Re: 3dfx Voodoo5 glitches

Have you tried using 1x speed setting on the AGP slot?

[Justin1091]

Re: 3dfx Voodoo5 glitches

Yes, including different bios revision for both the card and the motherboard. Card: every single BIOS from 1.06 to 1.18. Tried 3 different motherboards, with different BIOS options (UC vs USWC, shadowing, Aperture Size, AGP speed, etc).

The problem can be recreated easily: put bad voodoo5 in: crash. Put good one in: fine. Without changing any option, driver or anything.

[Sparkey55]

Re: 3dfx Voodoo5 glitches

Yes, including different bios revision for both the card and the motherboard. Card: every single BIOS from 1.06 to 1.18. Tried 3 different motherboards, with different BIOS options (UC vs USWC, shadowing, Aperture Size, AGP speed, etc).

The problem can be recreated easily: put bad voodoo5 in: crash. Put good one in: fine. Without changing any option, driver or anything.

What is the brand and power rating and +5v and +12V amps on the PSU?

[Justin1091]

Re: 3dfx Voodoo5 glitches

PSU 1: Aopen FSP350-60PN (350 watt)
+5V 30.0A
+12V 16.0A

I can't remember other PSU's I tried, don't have them anymore. Tried at least three, including higher wattages ones and different brands.

[Sparkey55]

Re: 3dfx Voodoo5 glitches

Since both +5v and +12v rails are used for voltage regulation down to a lower voltage set you can try to disconnect either rail one at a time from the card to try to determine if you have a weak or bad regulator section on the card. I have never tried this myself. YMMV.

[Sparkey55]

Re: 3dfx Voodoo5 glitches

It is possible that you could have a bad gpu BGA issue. I think the front chip runs all the time and the rear chip only kicks in during 3D detection rendering.