PC does not connect to monitors

[RajanM]

I have an Alienware PC with dual graphic cards and 4 monitors attached to them. I have had this setup for several years. The monitors started flickering occasionally over the last few days, then the screen went blank and they would not come back on. The monitors work fine and show power/standby mode.
I have taken the following steps one by one until now, though not necessarily in that order:
- Cleaned out the insides of the PC with a blower. There was a fair amount of dust in it.
- Unplugged all cables on the motherboard and reseated them
- Pulled out all RAM sticks and cleaned them. Used the blower to clean out the slots.
- Unplugged the graphic cards and cleaned them.
- Unplugged the CMOS battery on the motherboard and replaced it.
- Pulled out all the cables from the PC, including power. Pressed the power button for 60 seconds to drain power. Re-plugged all cables.

I noticed that the left fan inside the PC runs quite high for a bit. Sometimes, it seems to get stuck on high, and then when the PC is restarted, it works fine.
Over the past couple of months, another symptom noticed intermittently was when the PC was put on Sleep mode for a few hours, and then restarted, it would not show anything on the monitors although it would go through the startup process within. At times it would get stuck and have to be restarted through a forced hard reboot.

Any help would be appreciated. Thanks.

 

[Chicano]

The monitors showing a message such as "No video signal", "power/standby mode" it means the monitor is working on it's own cause there is no video signal and once one is detected the message changes to the mobo logo, on to BIOS post and Windows loading. If it's waking from sleep it should go straight to windows and when a second boot is required it could be the PSU is weak and a restart helps it develop a power boost.

1. Can you describe where/how all four monitors are connected?

2. Have you tried connecting only one monitor to see if that works?

3. Have you tried a different video port?,

4. Tried a different video card?,

5. Tried the onboard video if available?

6. When was the last time you updated the video card driver?

Optional tests:
Try/test the video card in another computer
Try a different PSU

Possible causes I suspect of:
a) Video card,
b) video card driver,
c) weak/bad PSU

 

[RajanM]

The monitors showing a message such as "No video signal", "power/standby mode" it means the monitor is working on it's own cause there is no video signal and once one is detected the message changes to the mobo logo, on to BIOS post and Windows loading. If it's waking from sleep it should go straight to windows and when a second boot is required it could be the PSU is weak and a restart helps it develop a power boost.

1. Can you describe where/how all four monitors are connected?

2. Have you tried connecting only one monitor to see if that works?

3. Have you tried a different video port?,

4. Tried a different video card?,

5. Tried the onboard video if available?

6. When was the last time you updated the video card driver?

Optional tests:
Try/test the video card in another computer
Try a different PSU

Possible causes I suspect of:
a) Video card,
b) video card driver,
c) weak/bad PSU

The problem was with one of the video cards. There are two video cards, unbridged. One of the cards was not working, causing the problem.
Thanks for your help.