I've been troubling with an issue over a week by now,
Let me explain it simply:
I have a strongly equipped PC and 4 LED televisions (2xSamsung and 2xLG)
2xSamsung Televisions are about 30 meters away from the PC case.
2xLG Televisions are about 15 meters away from Samsung TVs.
I 've used 30 meters HDMI cable and plugged in to a 4xHDMI Multipilier located nearby 2x Samsung TVs. Then I connected 2xSamsung TV's directly (with a 1,5 meter HDMI cable) and connected 2xLG Tvs with 15 meters HDMI cables.
The issue is; I was having very bad image quality. There are lots of red dots and lines on the televisions even in 24 or 23 Hertz. (above hertz I don't get any signal on the TVs)
And it is not only that, sometimes the TVs lose the signal completely then comes back after a few seconds.
I've used an HDMI extender (60 meters extender with 2 FTP CAT6 cables) instead of 30 meters HDMI cable. I then connected the HDMI extender output to he same HDMI Multipiler. The result is almost the same.
Just to test purpose, I've used a HD Satellite Reciever as HDMI output device instead of the PC. (I've replaced PC with a standard HD Satellite receiver) Surprisingly, all 4 televisions are perfectly okay.
What does it mean ? My PC is made up from high-cost equips (total cost is over $3,500)
Howcome a simple satellite reciever's HDMI output can be stronger than a PC graphic card that costs more than $200 itself ?