Black line on a dual monitor setup 1

[aking]

Hi, I am posting this cos i'm at my wits end.
I am sysadmin for a small office, the setup is dell workstations and dual monitors. I have a dell optiplex 745 with and ATI radeon 6350 grafix card connected to 2 dell 24" monitors.
The problem is that when both monitors are connected there is a horizontal black line which flashes on one of the screens - usually the 2nd screen. It appears intermittently and can be any position on the screen. Sometimes it flashes up when a key is pressed, sometimes moving the mouse in a certain way can make the black line appear, sometimes it vanishes for a while and i think it is fixed - then the black line reappears.
I have tested ALL the hardware so now i think it is the motherboard.
I have been able to do this quite easily because there is another Optiplex 745 in the office, it has a worse grafix card and less memory, it also has 2 monitors - the display on each is fine - no black lines whatsoever.
I have swapped literally everything (except the motherboard) between the 2 machines. Which is why i now think it must be the motherboard (sadly it is out of warranty or i'd just call Dell).
Oh yes, one more thing. When just one monitor is connected to this workstation then there are no black lines and everything is fine, i have even run dell diagnostics and it reports no problems.
This is possibly the most annoying/silly hardware problem i've ever had!
Can anyone think of anything to do apart from take a risk and buy a new motheboard?

 

[goombawaho]

Put in a different video card for testing purposes (PCI or AGP or PCI-E - whatever slot is available)?

Or are you saying you already swapped the OKAY PC's video card to the PC with the line?

If you could use a video card that utilized a different expansion slot type, you might escape the problem.

 

[aking]

Hi Goombawaho
I wasn't joking, i have tested ALL the hardware except the motherboard.
I have another dell workstation the same spec with a lower spec grafix card that is absolutely fine.
So i have swapped EVERYTHING - even the video leads, the dongles and the power cords between the 2 workstations.
The only thing i haven't swapped out is the motherboard - because it is so much work.

So in summary i have a workstation with black lines on one monitor when both are plugged in.
If i restart with just one monitor (either) it will be fine.
The workstation is fine otherwise (and has been for 2 years) in fact this is about the only problem is has ever had.
All of the hardware is fine on another workstation.

I'm posting this cos I'm at my wits end and this workstation is out of warranty!

 

[vacunita]

Can you take a picture of the line?

Have you checked the refresh rate settings? Is it at all possible it may be a scan line from the refresh that you can make out because its too low?



----------------------------------
Phil AKA Vacunita
----------------------------------
Ignorance is not necessarily Bliss, case in point:
Unknown has caused an Unknown Error on Unknown and must be shutdown to prevent damage to Unknown.

Web & Tech

 

[aking]

Haven't tried taking a picture of the idea - interesting idea - but what for?

The refresh rates are greyed out on 60Hz, resolution is on 1920 x 1200. I know this is the max but it is also the default.
This is where i get an advantage of having another identical machine in the office - this is exaclty the same on the working machine so i'm not worried about this.

When this started happening i downloaded the latest CCC (catalyst control centre) and installed on the black line workstation - it didn't make any difference. The working machine had an old version of CCC.

I have dropped the resolution down to 800x 600 on both monitors - it made no difference. One thing i was surprised about - even on ridiculous settings like 800x 600 on a 24 inch monitor it did not offer me the option to have anything but 60Hz.
If this was the only machine i had to play with i might think this was the reason, but when you have another machine which is rock solid on 60Hz with less system memory and an ati x1300 card (half the memory of the radeon 6350), but are otherwise identical what else can i blame it on but the motherboard?

i'd love to be able to prove it b4 i ordered one tho - if i order one and it doesn't fix it then i'm in trouble!
and thinking about it i haven't swapped over the power supplies either - but i don't think this could be a power issue could it?
(and of course both workstations ostensibly have the same psu).

 

[vacunita]

So we can see what it looks like, visual identification may lead to a solution.

IF they are identical hardware wise except for the video card, could you perhaps move the Hard drive to the working machine along with the video card, and see if the issue shows up there?

If it does then its not the MB, but maybe the Windows installation.

If it doesn't, do the same thing but from the working machine, if the line shows up with the working machine's HD and video card in the non working one, then you know its the MB.

----------------------------------
Phil AKA Vacunita
----------------------------------
Ignorance is not necessarily Bliss, case in point:
Unknown has caused an Unknown Error on Unknown and must be shutdown to prevent damage to Unknown.

Web & Tech

 

[rclarke250]

Take the video card,and hdd, and monitors and cables, and install them in the good machine, if it works ok, then you were right, and it needs a system board, If it has the same problem, it could be software.

 

[goombawaho]

What about my idea of putting a new video card using an alternate interface in the machine? It might get around the problem, but YES the problem would have to be with the MOBO after everything everyone has suggested has been done.

 

[aking]

Thanks for all suggestions.
If i'd had time to come in this weekend i would have swapped the hard disks, brilliant idea! Why didn't i think of that?

didn't try the new video card in an alternative interface idea cos there's only one pci-e x16 slot, don't have any other kinds of grafix card (other slots are pci and pci-e x1).

This pc is now at the back of the office so i try not to think about it.... I'll stay late one night or come in at the weekend and swap hdd's. If that doesn't do it i'll order a new MOBO off dell.

 

[FredWagner]

Before you swap out the hard drives, check to see what version of the Video Driver is in each machine - and do what you need to to get the machine with the problem using the same driver as the one without the problem.

Fred Wagner

 

[aking]

Yep, it was one of first things i did - updated the Ati Catalyst Control Centre to the latest version - no joy.

 

[SeadnaS]

Have you tried using driver sweeper before updating drivers?

http://phyxion.net/Driver-Sweeper/Driver-Sweeper/

 

[aking]

No, never used that one. If it's quick i might try that as a prelude to a rebuild. Currently this problem pc is at the back of the office so i don't have to look at it. Soon as i get some time i'm going to put in the windows disk and reformat. This thread convinced me that it was windows itself on that machine and I've always preferred to re-install windows as opposed to clean it.
(Although this is sometimes using a sledge hammer to crack a nut it also prevents future problems).

 

[aking]

To anyone who was curious:
I have just rebuilt my problem pc with a clean copy of windows 7 (reformatted the entire c drive). Have just installed ATI drivers and ultramon (dual monitor utlity), and it is Perfect . No horizontal black lines anywhere. Turns out it was software after all. Wow - i wasted so much time testing all the hardware. My rule of thumb remains in force - 80% of all IT problems come down to software.....
I don't know what part of windows it was tho cos i updated or re-installed the ATI drivers at least 5 times... but i'm glad it's fixed anyway.

 

[goombawaho]

I think it's more like 80.75%, but who's counting. Glad you fixed it.

 

[Gnomeface]

I've just had this problem, on a new Radeon card with the latest CCC, and (with help from an answer from another forum) fixed it. The problem was apparently caused by the video card being in overdrive mode - I never went into that option but I had tried increasing the speed on one monitor from 60Hz to its maximum of 75Hz before setting it back. The black line appeared soon after, with its position moving slowly down the second screen but only visible if there was mouse movement across an icon! I didn't connect this with changing the monitor refresh speed as I'd reset it back to the original and had been changing other parameters as well to get the colours to match.

The solution suggested was to turn off overdrive, in the CCC performance sub-menu, which stopped the black line instantly. I can't claim credit for the solution but as I was about to return the video card as being faulty, I'm really pleased.