display output keeps switching on and off!

[mTz]

Build a new system few days back, GPU and PSU are old though. Now the problem, GPU and on board hdmi both keep disconnecting and connecting display signals, much like when we would change channels on tv there would be a momentary black screen, except it keeps happening continuously in very quick succession. Used two different displays, drivers for both the gpu and integrated are installed. Its working on VGA fine. Also thin and small horizontal line appear which i first thought were part off the background and were shooting star!

on board hdmi is a lot worse as its output does not even get picked by displays most time.

System ::
i5 6500
asus b570 pro
hd6570
550 cooler master
8gb ddr4

PSU & GPU are part of a previous system(3yr old) whose motherboard(i belive) got defected, display would freeze and system would become unresponsive and wouldn't recover

 

[mTz]

Solved. HDMI cabel was the problem.