My name is Kong Arunsovath I have a problem that when I plush the old monitor to the new System Unite so my monitor cant display but the system is working. So I hope you help me to sult this problem for me. Hope to hearing from you soon.
Is the video not showing up at all, or only when it starts to load Windows, can you see the BIOS screen?
Do you have another monitor and cable to try to rule out a monitor issue? Check the cable connections, including the cable going to the monitor, some of them are screwed in and may come loose. Replace the video cable if no image, if the new video cable does not help, try a new monitor.
If you can see the BIOS screen, start the PC in Safe Mode, hit F8 at PC boot up. Select Safe Mode with Networking. See if you get the display then. If you do, download the latests drivers for your video card and install them. If you have an LCD, set the display to 800x600 at 60hz, if it's a CRT, use 75hz. Once you get a display normally, look up your monitor model number online and find out it's native resolution, then you can change to that from 800x600 so yoru screen looks better.