There is no image on the monitor, why?

Question

ASUS

UPD: On the old video card, with an analog connection, everything goes as expected. As soon as it comes to numbers - zero. The DVI cable, although old, is intact, not broken anywhere. There is no other such thing to try -_-
Suddenly. Today, after turning on the computer, I discovered a trick. The computer starts up, the load and hard indicator blinks, the BIOS goes through POST with a characteristic peak. But the monitor is still in standby mode. Vidyakha new, nvidia 1050. There is obviously a working old Radeon R7 240. It's the same on it.
Mother ASUS M5A97 LE R2.0. Embedded video is not provided. On the box with the mother, CrossFire support is indicated, respectively, there is a truncated second slot for a video card in half. However, pushing a video card into it does not make any progress. Monique is working, at least its analog output, since at the moment a laptop is connected to it via VGA.
The other day a couple of times there was a new phenomenon for me - 8 short peaks. How did they appear without letting the computer start, although the mother even then went through POST O_o. That is, I turn on - 8 short peaks - a short pause - POST peak - again 8 short ones.
Now I took out the battery, but I doubt that the reset will help. Who faced this? How to win? Where to look? What to try?

Answer 1

new, nvidia 1050 ... DVI old

Compatible? DVI types .