Having problems with 7600 GT AGP card. Monitor goes black.

Hello! First time posting, I've been fighting with this for awhile now and am at the end of my rope. I have an Intel Pentium 2.8 and a Leadtek 7600 GT AGP in my Case I recently purchased. I've been playing games since DOS, so I'm reasonably adept at the computer.

Whenever I run 3d games within a few minutes my screen goes black and the sound loops...I have to manually reboot to get back to the desktop.
All my drivers for my sound card and Graphic card are up-to-date.
Motherboard drivers, monitor drivers, Direct-X etc. are all up-to-date.
The card is not over-clocked nor running hot. My power-supply is a recently purchased expensive 400 Watt,the highest I could go with my Dell Dimension 4500. This card is a low powered card and shouldn't require more. I've checked the inside and everything seems to be connected well. 2-d games work perfectly, and my 3-d games work fine for a few minutes until the blackout. It does not disconnect from the monitor when it does this.
Everything else about my computer is running flawlessly and has been for a long time. I do constant up-dates and the registry is cleaned regulary.
Tested Ram and it came up fine.
I always disable Anti-Virus and any other backgroud applications when playing. I run the games at about 1024x768 and usually without AA or AF and I still get this.

Does anybody have any suggestions as I'm already going bald and don't feel like pulling out what little hair I have left?

Mike(Thanks for any help in advance)

You've been very thorough! The only other check I would suggest is swapping the video card. Take it to the store and see if they have another one and see if it works. If so, then there's a problem with your current video card.

follow-up

Thanks for the fast reply.
Well...I went back and tried some other games and it's peculiar. It actually works on games like Spellforce(the first one which is accelerated). But it won't work on Rogue Trooper or Condemned for more then a few minutes. I was able to play 3/4's of Tomb Raider Legend before it would conk out intermitantly. I keep going back to the heat or PSU but the PSU is 400w and cost me $120.00 and it was the highest I could go for my motherboard and everywhere I've read says this is fine for the card. The computer states the card is only running at about 56 degrees with the threshold being at 115 so that seems acceptable. I'm stumped.
Do I need to update AGP drivers as I thought they might be included in the latest NVidia release?
It does seem to have more trouble with more graphic intensive newer games.
I had recently bought a whole slew of games and would like to be able to play them.

I plan on getting a new PC next year but can't afford one now, which is why I bought the new card.
Is there any chance that my motherboard won't work well with the card because it's from 2002? Other then the CPU it's about the only thing not upgraded.
Thanks,
Mike

The only aspect you have not discussed is the memory... although you say it tests ok, you may not have enough... or it may be value ram which is not fast enough. If you purchased low priced memory, it may be slow or erratic. But you are limited, according to Dell, to two modules of DDR333 PC2700... slow by todays standard. But DDR400 PC3200 will work in most Dimension 4500's... if you don't mix DDR333 with DDR400 You need both modules to be the same brand, and high quality rather than "value" ram. It is very possible that your maximum of 1 GB is the greatest part of the failure. If you have two 512 mb modules but they have different chip configurations, you may have to experiment. You can get high quality Corsair, Crucial, or Kingston at www.zipzoomfly.com for about $59 each module.
The rest of your system, and the workup you have done are all first rate. It is not possible to fault anything you have done.
I would experiment with the drivers. Download both the current driver and the previous driver. But uninstall or disable what you have before you try the new ones, rather than writing over the exisiting ones.
Another possible problem could be cooling via the heat sink or fan. The Dell 4500 has some serious limitations in its CPU cooling fan, and heat sink.
Check the heat sink to assure that you have adequate thermal paste, and that the clamp-downs firmly hold the cooling system to the CPU. We have seen a lot of Dell 4500 heat sinks that had one corner of the plastic clamp-down version broken off. If you have the metal one, look it lover with bright light and your hands to assure it does not feel loose.
We find that the thermal paste is usually missing altogether.
Overall, you have a decent computer and you have done the right things.
But there are so many failures of video cards, that you should test yours in another machine, or test yours at a shop bench or try another one in your computer to look for differences.

Thanks...I ran Everest and if I'm reading this right I have 2 Infineon 512 pc2700 DDR SDRAM...could this be the problem? I was low on money at the time and picked them up from Office Depot.

Mike

I very much doubt that the speed or the amount of your memory is the problem. Your screen would not turn black and the sound wouldn't loop because you didn't have enough memory or because the memory was slow; the game would slow down instead. What you can do to test your memory is download and burn MemTest+ onto a CD-R and test your memory overnight one dimm at a time if you already haven't done this.

The problem is probably your video card like almcneil said.

Different...

If I have read this right, you recently bought a new video card, and thats when your problems arose. Did you put this card in the same slot as the old one came out? Have you checked your bios when you first start the computer? Maybe there is a change needed there. And i'm not sure if I read this right, but did you download the drivers for your card of the web or use the ones that came with the cd that came with the card? If you didnt download the newest ones, do that!

The AGP or any of the chipset drivers are not included with nvidia's drivers.

Not sure what you mean by this, but the only drivers I was talking about was the ones for his card......I've never heard of an AGP slot driver myself....

Thanks for all the replies.
I was having trouble with my old card which is why I bought the new card. (I believe the fan on it was not working correctly and it was basically doing the same thing except it would also disconnect from the monitor. I.E. the monitor light would flash and it doesn't go that far on my new card. I believe it was probably overheating.) So I bought the new power supply going from 250w to 400w and then the new card. My Nvidia drivers are taken from the Nvidia website, I have the latest, I also Uninstalled all drivers prevously and used driver sweeper to make sure it was a clean install. The installation disk for my graphics card does have a list of AGP drivers on it but I'm not sure which ones would be correct or if they are needed.
I only have one AGP slot so I can't try the card in another slot.
I get no slowdown with my games at all...they will run fine until at any point randomly the screen will go black and the sound will stutter-stick. I've checked all connections they seem secure. I've been playing Spellforce for a few hours now and nothing has gone wrong at all, Yet if I stick in Rogue Trooper or Condemned I barely get past the opening segment. I checked the Bios and other then updating the drivers ,which I did, I saw nothing in the Bios that might need changing.

Mike

No, I doubt that Infineon memory is part of the problem, as Infineon is superb memory... marketed mainly to the European community, but made in Germany and Czechoslovakia... as well as the US. (Infineon Technologies, AG - Munich) It is as good as there is, and is first tier memory, where they make the entire module themselves... no value RAM there as far as I know.

Well, Im thinking that the card is drawing more juice when you are playing more heavy graphic games and thats what is causing the black out. I am not sure of that but I know I was having graphics problems and getting a power supply that had dual 12v rails helped. I think I saw a post in here that someone said the watts are not as important as have dual 12v rails! Good luck.

That card does not consume great amounts of power. It is not the wattage that is important. It is the Amperage... and the ability of the power supply to adjust to the demands of whatever video card. The leap from 250 watt to 400 may not be much of a leap, if the 400 watt is poor quality... you should have paid $60 or more to get the better quality.
From what you describe, something is obviously wrong, but I don't think the power draw is part of it... but it is CPU, Cooling, Video Card, Video Card Driver, slow memory, or Power supply in some way.

The PSU I bought cost $125.00 and I was told it was the most powerful supply that the Dimension 4500 would take. I believe it was the size, i'm not sure. Here's what it says on the side...maybe this will help:

+5v@32A
+12V@32A
-12v@2.8A
+3.3v@28A
+55B2.0a
+6V
+3.3 V output=200W Max
continous Power 4.10 Max
Peak Power 450 W Max

I'm not an electrician but if you need any other info I will get it.

Thanks,
Mike

perhaps a bit off the wall, but if you have the monitor refresh rate set wrong it will cause some types of monitor to behave badly under severe load.

First, 512MB is on the low side for today's systems. More, you metion the problem happens with video intensive games. I'm inclined to believe it cold be that you do need more RAM. For any of my customers running video intensive application such as vide games, use at least 1GB. Anything less, it could compromise your system's performance. I'd still download/install the latest driver for your new video card too.

Sorry. I may not have mentioned it, (Thought I had) but I'm running with 1 GB of Ram. I've downloaded and tried the last 4 or five drivers for my video card...uninstalling the old ones with a cold boot each time. Also I've tried changing the refresh rate on my monitor from 60 to 100 and it still has the same problem. I will try the Heat sink check this weekend though as that I haven't done yet.

Thanks for the help,
Mike

Gut feeling says......

Wouldn't going to a HIGHER refresh rate worsen a overload?

Messing with settings, unless you are extremely advanced and experienced with a large number of setups, is not advised. I strongly recommend that you get your monitor and video graphics settings back to as close to normal as is possible.

This is an area that usually should not be changed anyway. When you have to also battle problems that the monitor and video card are already battling, it is very difficult to diagnose problem areas.... sometimes impossible.

I would prefer that you use a Windows disc, and drivers installs, to get you back through the R for Repair tools.

I'm talking about the refresh rate set on my Nvidia tool bar...the monitor is actually newer then my computer and I only use Refresh rates that it can handle. I leave it generally at 100. I've tried cranking it down to 60 on my nvidia toolbar and it has no effect on performance.
Thanks,
Mike