My computer doesn't communicate with my monitor help

[roserod2]

My pc seems to not go up, I don't know much, First I have a refurbished computer with a 450 w power supply and my op. system is microsoft xp.
All lites turn on but there is no communication to monitor from pc. It reads no signal. Days before it had happen but It came out running but now I turn it on and the lights of the cd &dvd rom & mouse go on but the monitor goes on no signal and nothig happens

[Broni]

Can you hear hard drive, and fans running? If so, try monitor in another computer.

[roserod2]

yes I can hear the fans . First I turn on the computer, im not sure about the harddrive but then the lights of my cd&dvd rom starts flash without stopping, the monitor lights greenwith a message of no signal  but then goes on standby(yellow light).When I move the monitors cable on my computer it turns on but rapidly goes of so I cant hit no keys, but then the mouse light is on. What could it be.Please help.

[roserod2]

I tried the monitor in my sister's computer which is not working also but the the monitorslight stays on in  black. It doesn't say no signal but also the light on the keyboard wont turn on, just the fans...

[patio]

Testing the monitor on a machine that's also not working isn't going to tell us much...

On your machine is this onboard video or an addon video card ? ?
When you stated moving the cable get's it going this would be my first suspect...

[roserod2]

Hi Patio i have been reading on the forums and I admire u alot, I don't know much of this but u are a genius. Thanks alot for being here and to answer Its an onboard video

[roserod2]

when I say that I move the keyboards cable and it lights this is just for half a second

[patio]

Check with the people you know to see if anyone has a spare monitor cable around and replace the one you have...Make sure everything is unplugged power wise when you switch them.
If this doesn't help anything you may have to have a friend temporarily install a video card in that machine to see if that works...
If it does then you will need to purchase a video card.
This would mean that your onboard video chip has failed.

[roserod2]

I'm sorry not the monitors cableit's the keyboards cable that I move

[roserod2]

ok  I will try that but then I would need help on installing that video card Thanks Alot , till tommorrow and thank you

[patio]

I'm sorry not the monitors cableit's the keyboards cable that I move

If this is the case then you need to unplug the machine and double-check ALL your connections on the back of the machine.

[roserod2]

Finally I could reply, anyway I double checked all the cables on my computer but it still didn't work, could it be the operatingsystem that it doesn't send nothing (no information) to the monitor or the mother board, I had the problem before but then the machine would suddenly work. Or is it the hard drive. I would have buy the video card.