Momentary loss of image. How to diagnose/treat?

Question

Video cards

Good day, comrades.
there is the following config:
1000Gb Western Digital (WD1002FAEX) 64Mb 7200rpm SATA3 Caviar Black
650W Cooler Master Extreme RS-650-ACAAE3-EU
ASUS 1024Mb GF GTX 650Ti GTX650TI-DC2T-1GD5 2xDVI, HDMI, VGA Ret
ATX Miditower Cooler Master Elite K350 RC- K350-KWN2 Black
Cooler Zalman (UNIVERSAL) CNPS8000B
DIMM 4Gb DDR3 PC10660 1333MHz Samsung (total 16GB - 4 sticks)
Gigabyte GA-Z77X-UD5H Z77 Socket-1155 4xDDR3, 5xSATA3, 3xPCI-E16x, 10xUSB3eSATA1, 2xUSB3.0, RAID, , 2xGbLAN ATX Intel Core i5-3570K
(3.40GHz) 6MB LGA1155 OEM
it has a system on it.
problem:
the point is the following. there is no relationship, but the screen flashes with the sound of connecting new equipment. or another option, without any sounds, the screen blinks. op black, op returned the image.
I removed all overclocking.
memtest drove for a day, the memory is in order.
did not change the axle. but drove stresslinux - it also blinks.
I don't have any ideas. the ability to stick the same or similar video card too.
wires changed (in terms of vga cable).
the problem is not stable. may not appear for 3-5 days, may at any moment (even at night when I sleep) appear 10-20 times per hour and calm down again. appears both under load (games, tests) and without load (remote connection, browser, a couple of instant messengers).
what are the ideas, comrades?
PS: started writing tags. blinked 5 times and calmed down.

Answer 1

Voltage surges in the power supply network. Install a stabilizer, it hasn't bothered anyone yet. Well, check your monitor.