PC posts but monitor gets no signal

Hello, there.

I have the issue mentioned above. When I try to turn my PC on, it posts (I can hear the beep) but the monitor gets no signal.

I know there are tons of questions similar to this one, but I've already tried many things.

The monitor and the cable have been replaced. Even the port has been changed (my video card has DVI and HDMI ports, I used to use the former but now I'm using the later).

I have already reseated and cleaned the RAM sticks and the video card, and already tried turning the PC with a single RAM stick. I reset the BIOS by unplugging an replugging the Clear CMOS jumper and, when it didn't work, by removing and reseating the CMOS battery.

I thought about checking the videocard, but my motherboard has no onboard videocard of its own, so I couldn't do it.

Is there anything else I can do?

Sorry for bad English and thanks in advance.