LG 65C9 TV Gets No Signal from Windows 10 DesktopPC After Each Restart

maxmt123 · 14 Jan 2020

Hello everybody, this is my first post so apologies in advance if I don't follow forum rules/etiquette.

I have a unique problem with my new LG 65C9 television that is driving me crazy. I want to use the television as a monitor for my PC, an HP Pavilion Gaming Desktop 690-0020 with AMD Ryzen 5 2400G processor. If I start the PC with no HDMI cable attached, and then plug in the cable after the PC is powered up, I get a perfect signal. However, if I restart the PC (or power the PC off and back on) the television remains on the "No Signal" screen. It's as if something about the Windows startup is not waking the television up, although the TV does get some signal from the PC, because a message pops up in the corner of the screen saying the hdmi port is now available.

I have gone through extensive troubleshooting with the HP help forum, following all the typical steps; uninstalling drivers, bios updates, AMD chip updates, clean install of Windows using the Media Creation Tool download, etc. There was about a 5-day period where I thought the problem was resolved, and then it went back to not functioning properly (maybe a Windows Update messed it up again, I can't be sure).

The TV functions perfectly with all other devices, including different laptop and desktop PCs I have tested. Similarly, the PC is functioning correctly with my old Samsung LED TV and a Samsung monitor I own. The problem must be with the communication between the PC and 65C9 on startup. I have tried different cables and different ports on each device with the same results. I feel like there is a setting that I have missed that would solve all my problems. Please help!

Here is my discussion on the HP forums in case it helps explain the problem and my troubleshooting process.

My windows version is 1909 (OS Build 18363.592). I assume my other specs will be visible in my profile. Thanks for reading!

A Guy · 15 Jan 2020

This is an OLED OLED65C9PUA correct? I am an almost 30 year TV tech, so I'll try and help from the TV perspective. First an easy test to try, if it works, also an easy, if not irritating, workaround until you get the issue resolved

Try to connect as you usually would, assuming you get the no signal. change the TV to another input and back to the input the PC is connected to. Does it now connect? If so, this is the easy workaround for you. Also tells me the TV is not making the HDMI handshake when you try to connect.

Do you already have the TV on, and on the HDMI the PC is connected to when you boot the PC? If so, try either having the TV off, and turning it on after booting the PC, OR have the TV on another input, boot the PC, then change inputs to the HDMI where the PC is connected. Do either of these methods result in a signal each time?

Which input are you using? I believe HDMI 2 is ARC on your TV? In any case, have you tried another input, regardless of which you are using now? The HDMI inputs are 2.1, I'm unsure if the cable type could be an issue?

A Guy

maxmt123 · 15 Jan 2020

Hello and thanks for your response. I tried your troubleshooting tips and unfortunately they did not result in any change. I tried multiple restarts on both HDMI 4 and HDMI 2, but the screen would stay on "No Signal" unless I unplugged the HDMI cable from the PC between restarts. You are correct about the model of the television being OLED65C9PUA, and HDMI 2 is arc compatible. I really think this is more likely a PC problem because the PC has given me connectivity issues with other monitors in the past. Maybe I have a bad HDMI port or graphics card...

My next step (over the weekend) will be redoing the BIOS and AMD chip update, and trying different ports on the PC using a displayport adapter. I am not very optimistic, and will also try any troubleshooting tips that people want to suggest in this thread.

Thanks!