Flashing screen Z87X-UD3H i7-4770k GT-640 2GB DDR5

[KirillRem]

Flashing(Blinking) screen Z87X-UD3H i7-4770k GT-640 2GB DDR5

Hello guys and nice to meet you. I'm new here and this is my first hackintosh.

MB: Gigabyte GA-Z87X-UD3H
CPU: Intel Core i7-4770K, OEM
COOLER: Corsair H75
VIDEO: Gigabyte GV-N640D5-2GI, GT640, 2048МБ, GDDR5, Retail
RAM: 2x DIMM DDR3, 8ГБ, PC3-12800, 1600МГц, Crucial CT102464BA160B
HDD1: SSD 250ГБ, 2.5", SATA III, Samsung 840 EVO Series, MZ-7TE250BW
HDD2: HDD 2ТБ, Seagate Barracuda 7200.14, ST2000DM001
WIFI: TP-LINK TL-WDN4800
POWER: Corsair RM650
DISPLAY: Philips 227E4QHAD using DVI -> HDMI cable
SYSTEM: OS X Mavericks 10.9.3

So I installed the system using unibeast + multibeast

Multibeast:



Everything is seems to be all right (Wifi, Sound etc).

The only one and very annoying thing is that my screen flashes every several second (to black and back). Can you please help me with that? What can it be?

Here is the link to the video:
http://youtu.be/9aFfGu1wKoo

I will be very grateful for your help!

 

[KirillRem]

UPD2: Using VGA it's still flashes but no so frequently. Maybe one time in two minutes. Different video outputs tested – the same with internal HD4600. Don't know what to do...(

UPD: It seems to be problem with DVI - HDMI connection or with DISPLAY.
I tried to connect thru VGA -> VGA and everything was ok, but quality of picture wasn't as sharp as with HDMI.

 

[KirillRem]

UPD3: So Finally I found that this is a problem with my video card. I disconnected Gigabyte GT-640 video card. And then connect dvi to hdmi cable to internal HD4600 video card. Everything is all right with it. No flashing, absolutely stable system now. If you have the same troubles with GT640 please let me know how you solve it. Thanks!

 

[NimhOfJoy]

Uh-oh. I'm having the same problem with the same video card with a pair of HDMI monitors I just bought. Did you ever solve this?