I have a ctx moniter says undectected mode

The 9-pin port on your PC tower is NOT a video port, it is a serial data port. All VGA connectors are 15-pin. Hooking up to the 9-pin port will not get you a picture. There should be a VGA port on the PC, or else a DVI an/or HDMI port. You can get DVI-to-VGA adapters that work, but only if the DVI port is an analog DVI, not if it is a digital DVI (DVI-D or DVI-DD).

So it seems you had a bad MOBO ,PSU or RAM.

can you give more info if there is any sounds comming from the tower

Check the pins in the monitor that plugs up to the back of the computer and see if they are bent.

I would recomend checking both ends of the connection cable to make sure they are secure and fully connected. If they are and it is still giving you trouble you can try using the monitor on another conputer. If the issue stays with the monitor then it is time to replace it. If the issue is only on your pc then it could be an issue with your video card/chipset.

If that is the case you can atempt to reinstall the video drivers by downloading updated drivers from the mfg web site for your video card. If still having issues then it may be time to replace/upgrade your video card to a new one.

go to properties in desktop n look for screensaver then power then look for monitor off time

You may need to replace the moniter cord or check the video card on the computer.

Video Card has a resolution setting higher than the monitor supports. The below works with XP, may work for Vista as well

Start the PC
Start hitting the F8 key repeatedly until you see a menu
Choose Safe Mode (make sure not to pick safe mode command prompt)
Once you see the desktop, right click on an empty area on the desktop, then choose properties

Find the resolution property in this program and bring it down. 1024 x 768 should be ok

Click on OK til the window disappears

Reboot

i) usually an computer enter's into power saving mode if computer monitor is not receiving any singals from the computer tower, so it has nothing do withur computer monitor(computer monitor is working fine), there is some problem withur computer tower.

ii) now try  removing all the physical connections going to computer tower(back side), wall socket  and replace them ....., (to avoid loose connections) 

   now see whether ur computer is turning on and working properly so that your computer monitor receive singals ....

  let me know what is happening

Thanking you

M. Sridhar

Hi...there,
That b'cuz your computer still running in power safe mode... All you need it to moved your mouse and it will log you back on....