Why am I losing DVI Signal to my two monitors?

killem2

Coastermaker
Ok here is the story. About a 2 months ago, when I was using my 8800gt, I would notice oh maybe once a week, my computer would lose signal to its monitors. This lose in signal would just be visual, the pc was still running. I verified this once, by downloading a large file just before I would go to bed and leave the pc running a loop of 3dmark 06 to see if I could get the monitors to lose signal. Sure enough it did but the file was also downloaded as well.

So I asked around and the general consensus was, your 8800gt is failing. Replace it. Ok, well I didn't want to, but if I had to, ok. So I got my HD 5850. And everything seemed ok, until about a week ago (got this on the 20th) my son booted up Burnout : Paradise and about 30 mins into the game It lost dvi signals and now its started to do it all over again.

When I had it on my 8800gt it progressively got worse and worse and crashed more and more often. Even when just dinking around on the web or just typing a document. Even after down clocking the 8800gt to as low as I possibly could it would still lose the signals.


Now retracking my steps the only MAJOR changes I know I have done is:

Installed Windows 7 64 bit right towards the beginning of December.
Upgrade Drivers for 8800gt.
Changed to HD 5850
Bought a new Samsung F1 1TB drive.
Bought a new Sound Blaster audigy card.

I have tried with both cards to downlocked my cpu back to 3.0ghz which I had it at a constant 4.0 for nearly a year and a half. And the problem has now still occured on both cards.

The strange thing is, not once when I was overclocking the HD 5850 with furmark, vantage, 3dmark 06, dirt 2 demo benchmarks and so on did I ONCE lose signal even for HOURS of looping.

Here are my exactly specs of my computer.

CPU: Dual Core E8400 @ 3.0 ghz (normally 4.0ghz) @ 1.4V when OC.

Ram : Corsiar XMS ddr2 800 4 gigs (2x2)

Video card: I have an 8800gt and hd 5850 both are at stock now. I have never oc'd the 8800gt

Hard drives: OS - Samsung TB Spin Point F1 drive, storage Western Digital, 640 GB drive (blue I believe)

PSU: XION Supernova XON-600F14R-201 600W - http://www.newegg.com/Product/Product.aspx?Item=N82E16817190012

MOBO: GIGABYTE GA-P35-DS3L - http://www.newegg.com/Product/Product.aspx?Item=N82E16813128059


My old OS was Vista home premium 64 bit, my new one is Windows 7 home basic 64 bit.

While I wasn't planning on upgrading my gfx card so soon, I was going to by mid march, but thinking my 8800gt was dying and i still wanted to use my pc, I went ahead and bought a new card anyway. However now it seems like it was never my gfx card.

What do you think it is??
 

b1lk1

Tech Monkey
Was he playing the game with a game controller of the keyboard? When I play games on my PC and I use a game controller, the video does occasionally go to sleep, but wiggling the mouse wakes it back up. I have no crashes though so if the PC is crashing there is another issue. Otherwise, the HD5850 sounds like the OS is turning off the LCD after a time of no keyboard/mouse activity and that is just a matter of changing settings.
 

killem2

Coastermaker
Was he playing the game with a game controller of the keyboard? When I play games on my PC and I use a game controller, the video does occasionally go to sleep, but wiggling the mouse wakes it back up. I have no crashes though so if the PC is crashing there is another issue. Otherwise, the HD5850 sounds like the OS is turning off the LCD after a time of no keyboard/mouse activity and that is just a matter of changing settings.

Most of the time it is with a controller. He plays ghost busters as well with the keyboard and mouse, and sometimes left for dead.

As far as the settings, I always switch those after a new isntall to power user where nothing shuts off unless I want to to. If that's what you mean.
 

b1lk1

Tech Monkey
I do believe that 8800GT was dying from the sounds of it, but the HD5850 (I have a HD5770 and my HD4830 did this as well) sounds like it is doing nothing out of the ordinary. Check your power settings, most likely the setting for turning off video with no activity is the culprit.
 

killem2

Coastermaker
I do believe that 8800GT was dying from the sounds of it, but the HD5850 (I have a HD5770 and my HD4830 did this as well) sounds like it is doing nothing out of the ordinary. Check your power settings, most likely the setting for turning off video with no activity is the culprit.

Ok thank you I shall check that out. I just didnt know if that was it with my son having it just crash while playing.
 

2Tired2Tango

Tech Monkey
Ok thank you I shall check that out. I just didnt know if that was it with my son having it just crash while playing.

In your mouse and video drivers you will find a power management tab... Make sure you check the box that says "Allow this device to bring the computer out of standby" (or similar)... There is an activity timer that is continuousely reset by mouse and keyboard activity. Depending on your drivers and power settings, unchecking this box stops the system from resetting that timer and your video can go to sleep and, for that matter, the whole computer will even go into standby while you're typing!

Also check your monitor's settings... Make sure the DDC/CI is enabled. This is a modes/activity communications channel for your video drivers. It might be that the monitor is not communicating with the computer and going into stanby all by itself.
 

killem2

Coastermaker
In your mouse and video drivers you will find a power management tab... Make sure you check the box that says "Allow this device to bring the computer out of standby" (or similar)... There is an activity timer that is continuousely reset by mouse and keyboard activity. Depending on your drivers and power settings, unchecking this box stops the system from resetting that timer and your video can go to sleep and, for that matter, the whole computer will even go into standby while you're typing!

Also check your monitor's settings... Make sure the DDC/CI is enabled. This is a modes/activity communications channel for your video drivers. It might be that the monitor is not communicating with the computer and going into stanby all by itself.


I found the check box for the mouse, the keyboard didn't have that management tab and neither did the video card drivers.

where do I find the settings for ddc or ci in windows 7?
 

2Tired2Tango

Tech Monkey
I found the check box for the mouse, the keyboard didn't have that management tab and neither did the video card drivers.

where do I find the settings for ddc or ci in windows 7?

DDC/CI is one setting. It's not part of Win7. You will find in your monitor's setup menus.
Not all monitors allow you to turn this on and off... Both mine do and I had the problem of the monitor suddenly going dark on one of my computers... That's why I mentioned it.

You may want to take very careful note of exactly what happens when the dark monitor problem comes up... some of the possibilities are...

1) The monitor goes dark, the Power led changes to "Standby" indication: In this case the computer has told the monitor to go to sleep via DDC/CI signalling.

2) You see a "No Signal" warning on the monitor, it goes dark, the power led changes to standby indication: The computer has stopped outputting a video signal to the monitor.

3) The monitor goes dark, there is no warning, the monitor's power led signals Active. The computer is still sending video signals to the monitor but you can't see them.

The third case is the most perplexing because it probably signals a lockup in your video cards or drivers such that it's still producing output but is not processing data. This is a common problem when overclocking.

The next time this happens, take very careful note of what state things are in... Is the tracking light in your mouse on? Do the CapsLock and NumLock keys on your keyboard toggle the lights? Is your hard disk spinning? etc. There may be additional clues you are missing...
 
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killem2

Coastermaker
Yeah that one I can rule out for sure I've ran furmark for nearly 30 mins at 1920x1080 8xaa and my cooler on the 5850 keeps it at no higher than 55c. This is at stock. Fan speeds @ 100%.

One thing i forgot to mention last night when playing burn out, for about 2 hours straight with no issues, i went to get up and my foot got caught on my controller cord which is hooked into the back of the pc jerked a bit, (still connected) and it caused it to lose signal then.
 

Tharic-Nar

Senior Editor
Staff member
Moderator
Loose connection? Bad cable? Broken solder on the card output socket. If you've had the same problem with 2 cards and both times used the same cable, could actually be the cable, or the port on the monitor. If you have another port on the monitor like another DVI or a VGA slot, try that.
 

2Tired2Tango

Tech Monkey
Loose connection? Bad cable? Broken solder on the card output socket. If you've had the same problem with 2 cards and both times used the same cable, could actually be the cable, or the port on the monitor. If you have another port on the monitor like another DVI or a VGA slot, try that.

Excellent suggestions.... Especially trying it with VGA connections.... If the connection doesn't break on different connectors with a different cable, you've narrowed it down rather a lot... A bad connector or a bad cable... most likely it would be a cable since the problem transplanted itself across two different video cards.

Also cleaning the connectors might help. The best way is with a spray can of Isopropolene contact cleaner. Alternatively you can dip the cord ends in rubbing alcohol (also Isopropoline) and then insert and remove the plug from your computer several times while it's still wet. Same on the monitor end... (Alcohol is non-conductive, so don't worry)

Of course there's the #1 rule of messing with wires... always pull on the connector, never the wire.
 

killem2

Coastermaker
I will try different cables but keep in mind, that is TWO cables that would have to have broken. Not saying it can't happen but two cables going out is odd. to me. I will try these idea's tonight too.
 

2Tired2Tango

Tech Monkey
I will try different cables but keep in mind, that is TWO cables that would have to have broken. Not saying it can't happen but two cables going out is odd. to me. I will try these idea's tonight too.

What do the two cables have in common?

Age? Usage? A third cable?

And that begs the question... Do both monitors always go out at the same time?

And then.... There is another connector people don't tend to think about in these situations... This could be a problem with your motherboard's edge connector... Perhaps you should try cleaning that as well... Take the video card out and polish the gold edge connectors with a pink pencil eraser (one of the soft ones). Then dip a small paint brush or soft toothbrush in alcohol and clean the connector on the motherboard. When you re-insert it, make certain it's seated properly and sitting in the connector without any stress...

The more I think about this, the more I'm convinced Tharic-Nar has the right idea... bad connections.
 

killem2

Coastermaker
They both go out at the same time when it happens. I did it on my 2 year old 8800gt and my 2 week old hd 5850.

The cable for the 19 inch I bought with my new pc because I was having issues with a previous dvi cable losing colors. The dvi cable that came with my 24 inch is also the same age.

When you say motherboard connector are you talking about the PCI slot?
 

2Tired2Tango

Tech Monkey
When you say motherboard connector are you talking about the PCI slot?

Yes... where the edge connector on the video card plugs into the motherboard. It's probably PCI-E but it's the same story. Edge connectors are notorously sensitive to dust and it doesn't take much at all to break a connection.

I once saw a computer crippled because a hair got into an AGP slot... took a while to figure that one out but the eventual fix was to take the card out, clean everything, reassemble, and away it went... We found the hair in the brush we used to clean the slot.

If you've been using that computer for 2 years, it's probably time you took all the cards out and cleaned all the slots... including the ones for your memory. You should probably also clean all the rear panel connectors too.
 
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