PS4 and TV link stopped working

Plugging in power or HDMI first doesn't matter, the instructions are there for the people who cannot figure it out themselves.

This sounds to me like an HDCP issue. Essentially, the PS4 wants to use HDCP via a "handshake", so it opens the HDMI connection, sends the HDCP info to the TV and waits for a response. The PS4 gets no response, shuts off the connection, and tries again. Likely after x number of tries, it disables the HDCP and proceeds that way.

You may be able to disable it manually by going to Settings -> System -> and turn off HDCP. Do note that without HDCP, certain apps won't work, such as most video apps.

I'm not 100% sure if the PS4 will still attempt an HDCP connection on bootup even if this is disabled, but it's worth a shot.

I would also suggest making sure that the HDMI cord is HDMI 1.4 compliant. The cord that came with the PS4 is, so try that if you're still using an older HDMI cord.

Finally, I would try another TV if this is still causing an issue.

If you do isolate it to an HDCP issue, then you have several choices:

• Certain powered HDMI splitters can essentially "strip" the HDCP. I purchased one last year for ~$30 which allowed me to record PS3 gameplay over HDMI.
• Many audio receivers can "strip" the HDCP. Getting an audio system with such a receiver may be a worth-while upgrade anyways.
• Getting a new TV that supports HDCP would also be a good idea.

EDIT: It is odd that the TV claims to be HDCP-enabled. The 8ms response time has nothing to do with it. This sounds to me like a possible defect in the TV or PS4 in how the devices handle HDCP.

One thing that I read online is that some PS4s have a slightly deformed HDMI port:

Later in the day, I got a call from Sony. They'd examined our unit and they figured out the problem. A piece of metal in the system's HDMI port was supposed to have been flush with the bottom of the port but instead had been bent upward, obstructing some of the pins in the port. It had been hard to see, though I imagine we would have noticed if we'd examined the unit more closely and not given it back. Nevertheless, we were told that that PS4 had been fixed. The Sony employee testing our unit used a pin to push the small piece of metal back down. They then plugged an HDMI wire into the unit and it worked. They even brought the unit to our office so we could see for ourselves.

The obstructing piece of metal in the formerly-broken PS4 had actually knocked some of the "teeth" out of the HDMI wire—the one bundled with that PS4—that we'd originally plugged into the unit, the Sony folks told us. We checked two other HDMI wires that we'd used during our brief bit of troubleshooting, and sure enough, they were missing the same teeth, too.

At this point, I would try connecting the PS4 to another HDCP-enabled TV (with HDCP turned on of course) and see if it works that way. If it doesn't show any issues, then the problem is your TV. If it does show up as an issue, then the problem is with the PS4.

I used to work for an ISP and there are some things that I can suggest assuming that you did not change anything yourself: - for best connection never use Wifi - do a speedtest from a wired machine that is not your PS4 and check the speed is at a minimum the same as you had before the problem if it is not - ensure that nothing has changed on the router on your end (check the config) and - call your ISP/provider and ask them to check if your subscription is still the same, if this is the case ask them to check the connection it is possible that due to the problems they had that your connection is configured at a lower speed