Computer and Screen erratically freezes and will not respond

[LeeBrown72]

I had an ongoing problem for over a year. It started infrequently and then became an every 5 minute thing. Whenever I tried to scroll on a website (with any of 5 different browsers and any of 4 different mice) or scroll or highlight a list on some other program, the computer would IMMEDIATELY FREEZE and NOTHING would respond. The screens would freeze and nothing would respond. Control/alt/delete, Restart or OFF buttons were totally inoperative. The ONLY way to re-start the computer was by manually turning off the Power Supply, wait a minute or so, and then re-plug or Switch the machine back ON. As a NOTE: the computer and mouse would work PERFECTLY while in Safe Mode w/without networking!! I downloaded and clean-installed all NEW Drivers for everything including my video card and even updated the BIOS for the mobo. No change. I replaced the Mouse (mice), Processor, HDDs, CPU Heatsink & Fan, the Power Supply and re-installed my OS. No change. Overclocked and underclocked the GPU and CPU and even changed voltages. I had changed everything except the rubber feet on the bottom of the computer... that is, everything EXCEPT my 2 year old $500 Nvidia Card. Now, I want you to know that my computer computed flawlessly (when it was working) everything was flawless... until I touched the scroll wheel. Instant freeze. Finally, as a last resort before turning this computer into a 40lb doorstop, I bought a $52 video card (an EVGA 210) just to see... voila’... perfection.
Can someone explain this to me?

 

[smorizio]

Could be the gpu chip overheated....slow fan or was a factory overclock card and they over volted it to far or one or more of the ram on the gpu went bad. There are gpu test programs that test your gpu ram...if the card under wARanty rma it.

 

[LeeBrown72]

Actually I have 5 fans plus the PSU fan in the chassis. One 90mm front chassis input fan blowing directly across the two 2TB HDDs, two 90mm exhaust fans (to create a good low pressure zone in the chassis and good airflow through the chassis), one 100mm fan copper bottom heatsink with MX-4 applied correctly, and one 80mm center fan blowing across the face of the mobo and video card area at a 45 degree angle. SpeedFan is installed and calibrated to 95% Max and nothing ever runs/shows over 60C. Normal GPU temps are 38-57C. CPU runs 38-56C. IHC runs at a steady 55-56C and is usually the highest temp in the chassis. But, the problem with freezing can occur the first time I touch the mouse after initial cold startup (boot-up) when temps are only in the 32-38C range. Also, I am the one who overclocked the CPU and GPU (I bought them both new) and I never overclocked more than 10% and then only temporarily (an hour or so just to test if there was any change). Voltages I only tweaked .3-.5 Volts. As far a RAM goes, I have 8G of fairly new 2G cards (which I had replaced a couple months ago thinking that they were the culprit).
Anyway, my real question was why the old Nvidia card caused my lockups and only while I was trying to scroll with the mouse... screen refresh rate maybe? Some other glitch in the card?
What I am trying to say is that when I replaced the old video card my problem was immediately resolved and everything runs perfectly. What I am trying to find out is ?why? Why had the old card caused this problem in the first place, and, if if anyone knows of, or if, there is a workaround (other than replacing the video card) to fix the problem.

 

[smorizio]

The only other thing I can give you as a tech is the old card and mouse could been using the same Irq or memory rang.