Hi guys,
I bumped into this problem after i bought a new TV a few weeks ago and realized that many of you are experiencing the same problem. PC not recognizing the TV. Or recognizing it but there is no signal or the resolution is changing, dropping the signal, blinking or black screen. I red almost every thread about this on various sites and realized that no one ever had a real solution so i digged into this. In my case even Nvidia and Samsung helpdesk had no real answers, they always suggesting re-install and firware updates, or replacing the HDMI cable but unfortunately it's useless. Sometimes it's the shitty cable but i tested everything, every HDMI input / output / cable / device / vga card / tv and individually everything worked fine, but when i tried to connect especially TV with PC then it failed to work.
So guys, i'm happy to inform you that I found the root of this annoying problem and the ultimate solution.
And it doesn't matter if you have Radeon or Nvidia VGA card and LG, Samsung, Sony or Phillips TV because it's not a software or compatibility problem. So regardless of the brands if you are experiencing this problem just read on and you will get a relief
Here's the thing:
This is an error typically between PC and TV, so it's not really happening between TV and say Blue-ray player, (you will undersand in a minute). Therefore testing with other devices and cables leads nowhere.
It's happening when a coax cable is connected to the TV. So it's not even a software or faulty hardware problem.
The faulty or almost spooky behaviour of the connection is caused by a ground loop because commonly TVs have non-grounded AC plug therefore the tv is not grounded. But PCs are always using grounded AC plug. Obviously, TVs are usually used for watching TV therefore they are receiving data thru cable TV coax cable. But this cable usually carrying extra voltage that is harmless for the TV because it cannot really go anywhere. But when you connect the PC with the TV that charge will be grounded thru the circuits of the TV -> HDMI cable -> VGA card/circuits -> PC's grounded socket. This symptom is called a "ground loop", in this case between a grounded and non-grounded device. So the starange behaviour of the VGA card is caused by that extra voltage traveling thru all the circuits, generating false digital information. So this is why it behaves so strangely / randomly or not even working at all. This extra voltage is usually not that strong to harm any of the circuits so it will not cause hardware errors, but it's enough to generate digital errors / problems.
I red on many forums that people solved this problem by unplugging the TV for a few minutes and when they plug it back in it usually works but it's temporary. It's because that extra charge will discharge by time when it's unplugged. But it's temporary and honestly, it's a pain in the ass always unplugging - plugging in the tv before use so it's not really a solution.
So here it is:
There is a little device called loop ground isolator for coax cables (or Cable TV Ground Loop Isolator). You have to insert this device in the coax line coming into the TV and that eliminates the unwanted extra voltage. It's a really cheap little device but it eliminates the root of the problems. I did this and now everything works perfectly.
I'm using Nvidia with Samsung TV so i already suggested to their helpdesks to put this information in the FAQ or something because many people experiencing the same problem. But as i wrote in the beginning it's not brand releated so if you have this problem just buy an isolator for a few dollars and your problem will disappear.
I hope this info will finally help everyone
Cheers!
Tamas