I'm trying to start an about 10 years old PC computer. But nothing is shown on the screen, and it beeps everytime I press a key on the keyboard. I can press Ctrl+Alt+Del to reboot the computer. The monitor is newer and seem to work with other computers.

I don't see anything from POST/BIOS at start or later. I have tried to change to another graphic card, but it didn't change anything.

What can I do to solve this problem?

Update: I have now tried with another computer (the one where the "another graphic card" came from) and I got the same problem. I doesn't show anything on the screen. Both these computers had a GeForce2 MX 400 graphic card. I tried with another computer screen it didn't work - it was showing "signal out of range".

So is the graphic card GeForce2 MX 400 too old for newer TFT-monitors?

I tried with a third computer so I know that the monitors are working, and both monitors work fine with that computer.