monitor not working

[mlynn0096]

hi, i am having trouble with my monitor. the monitor works until i hook it up to the computer, then the screen goes black and the light flashes green, i tryed 2 monitors and the same. i thought it was the motherboard so i replaced it,and it still does the same thing. help please:confused:
thank you marsha

[johnny_quest]

are you saying you tried the monitor on another computer and are sure it works?

[mlynn0096]

yes, it works on another computer, and i also tryed another monitor on my tower. my monitor works until i hook it up then it goes out and the light flashes off and on. thanks for the reply marsha

[mlynn0096]

help, please

[George Hallam]

have you tried a different D-sub/DVI leed

[Sylvander]

It all depends what your PC is in the process of doing when you connect the monitor.
And whether any signal is being sent out by the video card...
And if it is, whether it's getting to the monitor input along the signal cable. [This seems to be OK]

Have you connected the monitor when the PC is powered off and then switched on?
What happens then?
Does the POST complete with a single short beep, but with no display on the monitor?
Or is there "NO BEEP, NO COMPLETION OF POST, NO DISPLAY"?

[mlynn0096]

thanks for the reply, i have tryed hooking up monitor without computer on. it does the same thing, the light on the monitor flashes,and no pic. if i onhook the monitor from the computer it works, the light is solid green and i have a white screen
thank you marsha

[Sylvander]

1. "i have tried hooking up monitor without computer on. it does the same thing, the light on the monitor flashes,and no pic"
Do you mean by saying this that...
When you switch on the PC with the monitor connected...
Shortly after switching on...
The LED on the monitor blinks with a regular pattern...
But you hear no single short beep...
And there is no image of any kind displayed on the monitor?

2. "if i unhook the monitor from the computer it works, the light is solid green and i have a white screen"
In other words...
If [at condition 1 above] you unplug the monitor signal cable from the PC...
The monitor LED then goes to solid green and the monitor screen is displaying a solid white image?

3. KEY INFO NEEDED
(a) Are the fans running?
(b) Did the PC formerly give a SINGLE SHORT BEEP during POST?
(c) Does it now give NO SINGLE SHORT BEEP during POST?
(d) Is there any sign that the POST is running? [Blinking LED's (on optical drives or keyboard etc)]

[mlynn0096]

yes to question 1 & 2, the fans are running,but there are no beeps at all.there is no light on the keyboard or tower either. thanks for the reply. oh i also noticed that the switch on the back of psu doesn't work.
thank you marsha

[Sylvander]

1. Try a "bare-bones boot".
i.e.
Disconnect all but the most essential hardware.
e.g.
(a) Connect only PSU, mobo, CPU+heatsink+fan, internal speaker.
(b) Ideally the mobo would be out of the case on a non-conducting surface.
(c) With no on-switch connected, short the pins on the mobo to switch on.

2. If you're lucky, the POST will run, and test; the 1st RAM test will fail and warning beeps will be generated and sounded by the internal speaker.

3. Reconnect the video card and POST should again run and generate warning beeps.

4. Reconnect 1 stick of RAM and their should be no beeps and POST should complete.

5. Reconnect one more item of hardware and startup to see if POST still completes.

6. Continue this until either you have the HDD connected and the PC has loaded the OS, or connecting some item of hardware causes the POST to fail to run/complete. You then have the culprit.

[mlynn0096]

how do you short the pins on the board to switch on.i don't have a video card thank you marsha

[Sylvander]

"how do you short the pins on the board to switch on"
Usually done by placing the [broad] tip of an ordinary screwdriver across the pins for an instant.