Plasma TV doesn't like HDMI

[agra24]

I've been using a DVI to HDMI cable from my PC graphics card to my Plasma TV because HDMI to HDMI doesn't work. Can anyone explain to me why one works and the other doesn't?

 

[americanaudiophile]

Could be because the HDMI output of the PC may not be HDCP.
When you connect a PC to a TV with HDMI there can be a issue when they try to "handshake" which always happens when two things are connected with HDMI. Problem is that the TV doesn't always have it's hand out and the PC takes time to turn on the HDMI when it detects the TV.
The order you boot the PC and select the input on the TV it's connected to affects how they work. It may take more than one try. It may take 10 seconds.
Another possible issue is that all parts of the HDMI signal chain are supposed to meet the HDMI standard. When say a cable doesn't it may work sometimes and not others because other parts of the chain may be able to compensate. Even the particular HDMI input can make a difference.
DVI isn't affected by of these issues..

 

[agra24]

According to my graphics card's control panel it's HDCP compliant and the TV is as well. I've tried booting in every way imaginable but nothing works. I used to connect a raspberry pi 3 via HDMI to the same port in the past and after changing a setting on it that would "force hotplug" it worked normally. Should I try buying a new HDMI cable?

 

[americanaudiophile]

The cable can make a difference too.
All parts of the HDMI chain are required to meet the standard. Sometimes one part of the chain is better than the standard so it will tolerate a substandard cable or HDMI port. Replace that part of the chain with one that just meets the standard and it no longer works.
Hopefully the new version of HDMI that is coming out will be more fault tolerant.

 

[agra24]

But then again in my case it couldn't be the cable because I've also been trying to connect my Amazon Fire TV Stick which connects directly over HDMI. Could it really be an HDCP problem from the TV's side? In its manual it says that it's HDCP compliant... Even my old BluRay player, which I no longer have, worked via HDMI. Could the HDCP version be outdated?