Created attachment 113026 [details]
incorrect image

Dear Ben and Ilia. Thank you for your answers.

There is no BIOS on our device. We have u-boot instead of it. But that patch
from Ben is necessary even in kernel of the version 3.18.5.

The result of the monitor connection is in attach picture. The image is
incorrect. I tested both video cards GT520 and GT610, the result is the same.

There are some errors in the initialisation log.
nouveau E[   PFIFO][0000:01:00.0] PBDMA0: (unknown bits 0x00004000)
nouveau E[   PFIFO][0000:01:00.0] PBDMA0: ch 1 [DRM] subc 0 mthd 0x0000 data
0x00000000
.......
nouveau 0000:01:00.0: fb0: nouveaufb frame buffer device
nouveau 0000:01:00.0: registered panic notifier

Could the wrong work of video card  be the reason of these errors?  Or what
else is to be tested to find out the cause of wrong function.