monitors losing signal

[BlueFireZ]

Lately, when I turn on my computer the monitors lose their signals just
before the welcome screen comes up. They are fine before that.

If I reboot the computer the monitors work fine. They only lose the signal
about one in four times when I turn on the computer.

What could be happening?

Thanks

 

[Malke]

Lately, when I turn on my computer the monitors lose their signals just
before the welcome screen comes up. They are fine before that.

If I reboot the computer the monitors work fine. They only lose the signal
about one in four times when I turn on the computer.

What could be happening?

1. Loose cables.
2. Or failing monitor(s) - (how many do you have?)
3. Or failing video card.
4. Or failing power supply if you have a lot of monitors hooked up.

Malke

 

[V Green]

Next time this happens, try power cycling the monitors,
NOT rebooting.

See if they come up.

I have this problem intermittently with a Samsung 191T,
the problem seems to be that during the boot process, when
a lot of different resolutions are used, there is a brief instant
when the monitor thinks that one of them is invalid. It hooks
on to that invalid resolution and won't check to see if it went
away.

Power cycling fixes it every time.

As to why it just started happening for you, you might check
the following:

Fans / heatsinks on video card - make sure the fan is running
and heatsink not crudded up
Ditto for all cooling related stuff on motherboard
Power supply may have been marginal, and with use, has
fallen out of spec
Malke's suggestion to check cabling, etc. is a good one

 

[BlueFireZ]

I have two monitors. One is about three years old or less. The other is a
year old.
I will check the cables, etc. I pulled the comouter apart a little while ago
and might have not attatched a cable correctly.

Thanks.

 

[Pegasus [MVP]]

Lately, when I turn on my computer the monitors lose their signals just
before the welcome screen comes up. They are fine before that.

If I reboot the computer the monitors work fine. They only lose the signal
about one in four times when I turn on the computer.

What could be happening?

Thanks

A further reason, other than those mentioned by Malke and V Green, could be
that your display settings assume a value that is incompatible with your
monitor. Here is how you can find out:
1. Mark the code below with your mouse.
2. Click Start / Run and type this command:
Notepad "%UserProfile%\Start Menu\Programs\Startup\Display.bat"
3. Click OK and allow a new file to be generated.
4. Click Edit+Paste to get the code into the notepad screen.
5. Save and close the file.
Windows will now record your display settings each time you log on. To
examine the settings, open the file c:\Display.txt. You will see lines such
as this one:
Sun 05/04/2009 18:41:29 Display=768Hx1024Wx16 colours
Are they the same each time?

@echo off
set VB=echo ^>^>c:\TempVBS.vbs 0>c:\TempVBS.vbs
%VB% Set oWMIService=GetObject("winmgmts:\\.\root\CIMV2")
%VB% Set cItems = oWMIService.ExecQuery( _
%VB% "SELECT * FROM Win32_DisplayConfiguration",,48)
%VB% For Each oItem in cItems
%VB% Wscript.Echo Date(), Time(), "Display=" ^& ^
oitem.PelsHeight ^& "Hx" ^& oItem.PelsWidth ^& ^
"Wx" ^& oItem.BitsPerPel ^& " colours"
%VB% Next
cscript //nologo c:\TempVBS.vbs
del c:\TempVBS.vbs

 

[BlueFireZ]

Thanks.
I will figure out what all that means and check everything.

As I said to Malke, I opened the computer to clean it a couple of weeks ago.
The fans were working fine and nothing looked cruddy. I wonder if I loosened
the video card or something?

Thanks again.

 

[Pegasus [MVP]]

Lately, when I turn on my computer the monitors lose their signals just
before the welcome screen comes up. They are fine before that.

If I reboot the computer the monitors work fine. They only lose the signal
about one in four times when I turn on the computer.

What could be happening?

Thanks

Oops, slight mistake in my code. Use this one instead:
@echo off
set VB=echo ^>^>c:\TempVBS.vbs 0>c:\TempVBS.vbs
%VB% Set oWMIService=GetObject("winmgmts:\\.\root\CIMV2")
%VB% Set cItems = oWMIService.ExecQuery( _
%VB% "SELECT * FROM Win32_DisplayConfiguration",,48)
%VB% For Each oItem in cItems
%VB% Wscript.Echo Date(), Time(), "Display=" ^& ^
oitem.PelsHeight ^& "Hx" ^& oItem.PelsWidth ^& ^
"Wx" ^& oItem.BitsPerPel ^& " colours"
%VB% Next
cscript //nologo c:\TempVBS.vbs>>c:\Display.txt
del c:\TempVBS.vbs

 

[Malke]

Thanks.
I will figure out what all that means and check everything.

As I said to Malke, I opened the computer to clean it a couple of weeks
ago. The fans were working fine and nothing looked cruddy. I wonder if I
loosened the video card or something?

If you had loosened the video card you would have no picture and you'd be
getting a series of beeps when you started the computer. However, one of
the monitor cables might not be making a tight connection from either end
so it is worth checking.

Malke