Constant issues with AGP video cards - am I doing something wrong?

Discussion about old graphics cards, monitors and video related things.

Constant issues with AGP video cards - am I doing something wrong?

Postby moistyalf » 2018-8-10 @ 14:30

I seem to have the worst luck with old video cards... Basically my issues started about a year ago now. My retro gaming PC is a pentium II based system with an earlier style of AGP slot. I had been running a AGP TNT2 in it for some time without any issues, but after sitting for some time the system decided to beep incessantly as if there was no video card installed. I tried another TNT2 and a newer geforce card of some sort but it decided it hated all of them despite the cards working fine in a pentium 4 system. So i put it down to a bad slot and put up with a PCI s3 virge until I could acquire another board.

Well a few weeks ago I picked up a similar board with a slightly faster 266 PII in it which ran fine. So i installed my TNT2 into it and it worked ok for a few hours before deciding to do EXACTLY the same thing as the other board on boot, acting as if there was no card installed at all. So I swapped in a working s3 Trio card and it came back to life for another few hours before deciding it didn't like that card either. So now I have two boards which seem to hate AGP cards which worked in other systems previously.

At this point I feel like the tnt2 may be somehow damaging the boards but I really hope this isn't the case and it does work in other systems so i'm out of ideas. And I don't know how much longer I can put up with an s3 virge. Am I doing something stupid? Any advice is appreciated.
moistyalf
Newbie
 
Posts: 9
Joined: 2018-8-10 @ 14:13

Re: Constant issues with AGP video cards - am I doing something wrong?

Postby shamino » 2018-8-10 @ 15:14

What motherboards did this happen with? Is this a TNT2 Ultra or a plain TNT2? The Ultras were electrically demanding for their time. Not sure about the plain TNT2.
Since it worked for a while and then died, it sounds like it's possible the board was overloaded by the card. I don't know if it's plausible for that to happen with a plain (and non-defective) TNT2, but the Ultra was definitely known for killing some boards.

Many early AGP motherboards use an onboard voltage regulator to provide the 3.3V power supply to the AGP card. Often, that regulator isn't robust enough to power the more demanding cards that started to be released when 3D took off.
A documented example is the Asus P2L97. Older revisions had this problem, and Asus published a rework procedure to modify them.

If this is what happened, then once the onboard regulator was damaged it would become weak or completely dead, so lower powered cards also would stop working on such a board.
User avatar
shamino
Oldbie
 
Posts: 1390
Joined: 2013-1-24 @ 13:45

Re: Constant issues with AGP video cards - am I doing something wrong?

Postby moistyalf » 2018-8-10 @ 15:53

shamino wrote:What motherboards did this happen with? Is this a TNT2 Ultra or a plain TNT2? The Ultras were electrically demanding for their time. Not sure about the plain TNT2.
Since it worked for a while and then died, it sounds like it's possible the board was overloaded by the card. I don't know if it's plausible for that to happen with a plain (and non-defective) TNT2, but the Ultra was definitely known for killing some boards.


The card is a regular TNT2 m64, so nothing special there. As for boards, the first one was a Gigabyte 686lx4, and the new one I'm not actually sure what it is, no brand name anywhere. I did see it mentioned somewhere and it was a name i'd never heard of before. Almost looks like a copy of the gigabyte though, same IO layout and beep codes. But it does sound like it could be a voltage regulator. If i can track down where it is i'll see if I can test it.
moistyalf
Newbie
 
Posts: 9
Joined: 2018-8-10 @ 14:13

Re: Constant issues with AGP video cards - am I doing something wrong?

Postby moistyalf » 2018-8-12 @ 06:24

Well, I put the PCI card back in and it looks like this second board is totally fried now, after the s3 card displays its info, the board posts but then just shows flashing garbage characters across the screen and goes no further. Looks like i'm going back to my original board.
moistyalf
Newbie
 
Posts: 9
Joined: 2018-8-10 @ 14:13

Re: Constant issues with AGP video cards - am I doing something wrong?

Postby shamino » 2018-8-12 @ 07:41

I don't think an M64 takes much power, so that makes the previous hypothesis seem a lot less likely. But I suppose the card could be faulty and drawing excessive current.

If you have a multimeter and are comfortable probing around with it, you could try checking voltages while the board is powered and attempting to run. If you find any voltages to be low it would at least give some explanation of the problem (but not the root cause).
5V and 12V are the easiest since they're on drive connectors. The PSU's 3.3V is on orange wires at the motherboard connector but as mentioned, some boards don't use that rail and instead have an onboard 3.3V regulator. I don't know if that's the case for yours.
You can find the 3.3V that's actually in use on some pins of the DIMM, PCI, and AGP sockets if you look up a pinout for them. There might be easier places to find it but those definitely have 3.3V power routed to them. If you go after those pins directly then I'd wrap the probe with tape to avoid shorting to anything adjacent.

CPU voltage is usually easy to find at the large metal tab on the back of half of the MOSFETs near the CPU socket. Half of them will show 5.0V and the other half will show Vcore. But some early Slot-1 boards might be designed differently than what I'm thinking of.
User avatar
shamino
Oldbie
 
Posts: 1390
Joined: 2013-1-24 @ 13:45

Re: Constant issues with AGP video cards - am I doing something wrong?

Postby moistyalf » 2018-8-12 @ 14:29

shamino wrote:I don't think an M64 takes much power, so that makes the previous hypothesis seem a lot less likely. But I suppose the card could be faulty and drawing excessive current.

If you have a multimeter and are comfortable probing around with it, you could try checking voltages while the board is powered and attempting to run. If you find any voltages to be low it would at least give some explanation of the problem (but not the root cause).
5V and 12V are the easiest since they're on drive connectors. The PSU's 3.3V is on orange wires at the motherboard connector but as mentioned, some boards don't use that rail and instead have an onboard 3.3V regulator. I don't know if that's the case for yours.
You can find the 3.3V that's actually in use on some pins of the DIMM, PCI, and AGP sockets if you look up a pinout for them. There might be easier places to find it but those definitely have 3.3V power routed to them. If you go after those pins directly then I'd wrap the probe with tape to avoid shorting to anything adjacent.

CPU voltage is usually easy to find at the large metal tab on the back of half of the MOSFETs near the CPU socket. Half of them will show 5.0V and the other half will show Vcore. But some early Slot-1 boards might be designed differently than what I'm thinking of.


I'll have a probe around with the meter when I get a chance, i've put the first board back in and I now have a working machine at least (still no agp though). I also threw together a socket 370 celeron system from parts I had laying around (trying to hook up some scsi scanners to play music and having a world of issues with drivers). I tried some of my agp cards in that system (not the suspect board killing tnt2 though) and couldn't seem to get much life out of any of them either. So maybe the board failed in such a way that it is now zapping any agp cards I put in it? Will definitely check voltages next chance I get.
moistyalf
Newbie
 
Posts: 9
Joined: 2018-8-10 @ 14:13

Re: Constant issues with AGP video cards - am I doing something wrong?

Postby cyclone3d » 2018-8-12 @ 15:43

What power supply are you using? How old is it?
User avatar
cyclone3d
l33t
 
Posts: 2303
Joined: 2015-4-08 @ 06:06
Location: Huntsville, AL USA

Re: Constant issues with AGP video cards - am I doing something wrong?

Postby moistyalf » 2018-8-13 @ 07:27

cyclone3d wrote:What power supply are you using? How old is it?


It's original to the case afaik so pretty old. The power supply in the pentium III system i built is a lot newer and I have had no troubles with it and the cards refuse to work in it either. I'll give it a go with a different one and see if anything changes.
moistyalf
Newbie
 
Posts: 9
Joined: 2018-8-10 @ 14:13

Re: Constant issues with AGP video cards - am I doing something wrong?

Postby moistyalf » 2018-8-13 @ 12:19

Well, I think i worked it out. After checking all the voltages and messing with cards it started working again for a little bit. Turns out the AGP slot just needed a good drowning in contact cleaner. After that, all of my AGP cards now work just fine. Hopefully it stays that way. Thank you for the suggestions though!
moistyalf
Newbie
 
Posts: 9
Joined: 2018-8-10 @ 14:13


Return to Video

Who is online

Users browsing this forum: PC Hoarder Patrol and 0 guests