09-22-2019, 11:44 AM
Join Date: Sep 2019
Asus American Megatrends 1905 BIOS
Asus P8H77-V Motherboard
32 gig fast RAM
ASUS HD 5450 Silent Graphics Card
Windows 7 64 bit
3 Samsung Evo Hard Drives
Duel Monitor Display 2xHP w1907v
1 Monitor in to the Grapics Card VGA Port and the other into the DVI port via a DVI to VGA Adapter.
All updated with latest appropriate drivers from ASUS (for the chipset, and Samsung.
Is there anything on the Motherboard that can become faulty and cause flickering or drop outs in the video signal to one monitor but not the other?
Maybe a componant failing or a driver or IRQ issue (grabbing at straws here)
It is an old machine that has performed perfectly until now and the above issue started.
Before I explain fully I will just say that I have tried 3 different graphic cards now, ASUS HD 5450 Silent, ASUS GeForce GT 710 and a ASUS Radeon R7 240, and they made no difference with the flickering happening regardless. I also tried the Motherboards on board Graphics ports (it has a VGA and a DVI) and I could not replicate the flickering.
For each of the Graphic Cards only the display driver was installed, I did not need things like 3D and all that stuff plus the computer is not powerful enough for that.
Before installing a different card I booted into Safe Mode and did a clean uninstall of the previous cards driver/s.
The windows install has been slim lined taking out bloat ware and system services not needed and has been stable as a rock and fast.
The problem is with the primary monitor (the software sees it as Monitor 1) which flickers on and off and when I say flicker I mean the video feed to the monitor and not the mains power.
The feed will be fine for 10 - 15 seconds then will go to black for a second before coming back. In another 30 seconds it happens again, maybe 10 seconds it happens again and so on.
This happens only to the primary monitor (Monitor 1) and Monitor 2 performs perfectly.
This is what I have tried to cure it and I did the below steps for each graphics card.
Tried moving the graphics card to my only other PCI slot but it made no difference
Then for each slot...
Swapped the video cables around so that Monitor 1's now went to Monitor 2 - no difference
Swapped the cables at the back of the card so the one that was in the VGA port was now in the adapter on the DVI port and the other was now in the VGA - No difference.
Tried different video cables for each monitor - No difference.
Plugged each monitor in turn in to the Motherboards own VGA and DVI ports to test it was not a monitor or cable issue and ran a couple of CPU intensive programs - both monitors performed perfectly but as I can find no way of extending the screen from Monitor 1 across to Monitor 2 (like you can with a Graphics Card) I could not replicate the exact conditions.
I then installed a spare SSD and performed a clean install of Windows and repeated all of the above tests and got the same resuilts.
One thing that maybe of use is that I discovered while installing windows on the spare SSD that If I hard boot the machine (not a reboot but a power off) with only one monitor then there is no issue as long as I do not try and change the screen resolution. Regardless of whether I use the VGA port or the DVI and no matter which cable I use the flickering is gone. If I then turn the computer off and reattach the 2nd monitor, upon booting the flickering returns on Monitor 1. It is worth clarifying that it does not matter which monitor I use, as long as there is only one attached to the computer then there is no flickering.
However as I said above if I try and increase the screen resolution even slightly then Monitor 1 starts to flicker even if it is the only one installed. The higher the resolution the worse it gets.
I have tested this on all three cards and the results are the same.
I am beginning to wonder if this is a Motherboard issue such as control set or driver (I may be talking rubbish) that regulates or controls the video signal from the CPU? and then sends it to the PCI slots?
Maybe some settings, services or IRQs that need changing? I have no clue...