Screen Goes Black, Fans Still Running

This error first occurred about 2 weeks ago. While the PC is running, on a few occasions it happened while playing a video, the screen goes black then the audio stops about a second or so after. The monitor shows inactivity but all the fans in the case are still running gfx card, CPU & power supply. I had had one of my RAM sticks go bad before so I removed another and it booted up and the problem didn't occur for a while. But then it started happening again and more frequently, now to the point where the display barely makes it to the windows start up screen. I replaced the gfx card to this hasn't helped. Is it the MB? Should I buy some RAM? Power? What is life?

I'm not sure what my next move is. Help would be really appreciated. Thanks.


MB: GIGABYTE ATX LGA1366 Intel X58
RAM: Corsair DDR3 1600MHz (currently one stick of 2GB)
CPU: Intel Core i7-930
GFX: nVIDIA GeForce 210 1024MB
Power: Corsair TX 750 W

 

When troubleshooting any electronics, you always want to ensure you are supplying good, clean, stable power - especially before replacing any parts. So if me, I would swap in a spare or borrowed known good PSU and see what happens.

Note the fans still spinning simply means the PSU is outputting some power on at least one rail. But the PSU is required to output +12V, +5V and +3.3V within a ±5% tolerance range and any one of them could be bad but still allow the fans to spin.

Not sure I can answer that but as for what is "left" no doubt with only 1 stick of 2Gb of RAM, Windows is beating the heck out of your hard drive constantly accessing the Page File. So once you verify power, I agree to test your RAM. And if me, I might just consider replace that 2Gb stick with all new RAM. 4Gb if you are running 32-bit Windows, 8Gb if 64-bit.

 

Thanks for the response guys.

I'm running Windows 7 64bit. The single stick I'm using is one I tested and it passed.

I wish I had one of those and I've got no friends with desktops. Any parts going in to this baby would have to be bought.

So I guess my last question is, since the RAM passed the MemTest, what would be your guess as to who the culprit is?

 

The problem is no software based memory tester is conclusive. If MemTest reports the RAM is bad, it is bad. But MemTest (and all the other software based testers) may report the RAM is good (or has no errors) but the RAM still fails when installed, or when paired with other RAM. To conclusively test your RAM, you need to use sophisticated and very expensive test equipment, like this $4,000 Eureka Express DDR3 DIMM Memory Module Tester.

If you cannot find a trusted friend or relative that will let you borrow their PSU for testing, then you might consider taking your PSU to a trusted shop for testing or just buying a new PSU - especially before buying anything else. Because you have had multiple hardware issues (a symptom of bad power), and you already replaced your graphics card, replacing the PSU would still be better than assuming it is your motherboard.

Replacing a PSU is just swapping it in. Replacing a motherboard is a much more complex physical task. And unless you can find an exact brand and model number, it will involve updating a whole bunch of devices drivers in Windows that may force a fresh install of Windows. Plus you will have to remove and replace the CPU too (always risky due to mishandling and ESD). Unless you can find an exact replacement motherboard (or recommended replacement by the same motherboard maker if your model is no longer available) you will likely need to purchase a new Windows license too - because a new motherboard is considered a new computer and new computers need new Windows licenses. The ONLY exception to that is with a full "Retail" Windows license - but the vast majority are OEM (they came preinstalled on the computer). And a new motherboard may not support your old CPU or RAM either.

So buying a replacement PSU would be cheaper than a new motherboard. And having a spare PSU on hand is not a bad thing if it does not fix the problem. PSUs don't go obsolete near as quickly as motherboards and CPUs do.

If you do go with a new PSU, get a good one. One that is 80-Plus certified, at least Bronze, though Gold is better.