LG CX (OLED55CX5LB) Disconnect/Reconnect Issue when Gaming or Browsing

GhostOfJericho

Novice Member
LG CX (OLED55CX5LB) Disconnect/Reconnect Issue when Gaming or Browsing

Hi AVForum, hope whoever reads this is doing well.

I've been a lurker here for a while (just created an account), and appreciate the knowledge and respect everyone shows here. Which is why I'm looking for help if possible. Sorry, this may be a long post; my issue has been going on for nearly a year. I also want to include all the information AVForum members could possibly need, in an attempt to be as helpful as I can.

tl;dr: New LG CX, constant disconnect/reconnecting occurring in desktop use and PC gaming. Have been troubleshooting for nearly a year. New cables, PC's and endless settings changes in an attempt to fix it.

I purchased an LG CX (OLED55CX5LB) from John Lewis back in October 2020. I primarily use it for content consumption and PC gaming
Since purchase, I've had frequent disconnect/reconnect issues. This is: "Instant Game Response" flicker - Disconnect - Reconnect - "Instant Game Response" flicker; occurring frequently in fullscreen games, windowed games, borderless windowed games, normal desktop use like internet browsing, etc. As well as occurring every time I quit a game.
Software Version: 3.23.15 (Current version is 3.23.25; issue persists regardless)

My current PC is an AMD 5600x, and an RTX 2070 Super. I borrowed my mates RTX 3070 to make sure it wasn't HDMI 2.1 related (didn't make a difference), even though Nvidia confirmed the LG CX as G-Sync compatible with an RTX 2070. My previous PC was an Intel 3930k with the same 2070 Super; both had the same issue.

Frustratingly, my PC needs to be a distance from my LG CX.
I initially had some no name brand 10m HDMI 2.1 cable. With the issue of course existing, and fixes PC side not working (more on that later), I later purchased a certified 5m Maxonar HDMI 2.1 cable (non AOC) in May 2021. The issue continued.

Amazon product

After more PC testing (including the RTX 3070 test), and discovering that HDMI 2.1 cables over 10ft ideally needed to be AOC, I saw on this forum that a brand named Ruipro were extremely respected and recommended. So, after literal months and frustrating hours of my life spent troubleshooting the issue, I bit the bullet and purchased a 10m Ruipro 8K AOC HDMI 2.1 for £150. The problem persisted.

Amazon product

Here are some examples of what happens:

  • What reliably happens every time when quitting a game, and what can just happen when browsing my desktop:



  • Borderlands 3: External recording to show display. This game gets resized, whilst the game thinks it's still fullscreen. Not fun to fix. Please ignore the cable management; I've been endlessly pulling the TV in and out during troubleshooting.



  • Minecraft: Screen recording, audio with disconnect/reconnect sounds, visual stutter, notification of "G-Sync display connected". I didn't pause the game in this clip.




Other games have ranged from being fine after the issue occurs, to peripherals no longer working until I Alt-Tab, to game crashes, etc. Which is why I thought it was PC side this whole time. I also have a 144Hz 1080p DisplayPort monitor that never has any issues. Sometimes it wont do it for hours, sometimes multiple times an hour; always when quitting games.

PC troubleshooting steps have been:
  • GPU driver rollbacks, reinstalls, and updates. A completely different GPU tested.
  • Nvidia Control Panel settings changes (lots of, more details if required)
  • Endless OS settings changes (more details if required).
  • Complete Fresh OS installs. an instance of only a single game installed to test the issue. So no other programs could be the culprit. Issue persisted.
  • Completely new computer with all new components aside from the RTX 2070 Super; which is why I initially thought it was a faulty GPU.
  • Lots of LG CX settings changes (more details if required), factory reset, different HDMI port, etc.
  • Turning HDR on and off Display and Source sides; no difference.
  • Turning Instant Game Response off makes no difference.
  • New cables.
  • Custom Resolution Utility; changing the VRR range.
The real reason this has been such a slow process. Change a setting, then wait for it to happen again.
The cables have always run around a bed, with no power sockets near them (don't know if that makes a difference to high end cables). I have also run it directly under the bed just in case there was some weird interference.

Ultimately, I'm thinking the TV itself is faulty in some way, as I've been thorough in my troubleshooting.

What are your thoughts? Anything I could have missed? If you agree with my believing that it's the TV, whom should I contact first? John Lewis would be my preference, as I have had a good past experience with them, along with a 5 year warranty on this TV. Should I contact LG first? (would rather not; no idea how their customer service and aftercare support is). I also have the CX insured with John Lewis Protect Plus, run by Domestic & General. Should I go to them first?

Any help would be hugely appreciated; It's been driving me absolutely insane.

-Grant
 
Last edited:

Dodgexander

Moderator
For testing purposes move your PC closer and try a shorter HDMI cable. 10m was already long for HDMI 2.0 signals, let alone HDMI 2.1.

I don't think the long cables work very well, even certified ones. Reviews are usually full of people stating they have issues.

Most guides are based on HDMI 1.4, or HDMI 2.0 and say 25ft is max for a cable, its going to be a problem using such a long HDMI 2.1 cable as HDMI 2.1 carries a lot higher bandwidth signals...10m is probably already too long for HDMI 2.0.
 

GhostOfJericho

Novice Member
For testing purposes move your PC closer and try a shorter HDMI cable. 10m was already long for HDMI 2.0 signals, let alone HDMI 2.1.

I don't think the long cables work very well, even certified ones. Reviews are usually full of people stating they have issues.

Most guides are based on HDMI 1.4, or HDMI 2.0 and say 25ft is max for a cable, its going to be a problem using such a long HDMI 2.1 cable as HDMI 2.1 carries a lot higher bandwidth signals...10m is probably already too long for HDMI 2.0.
Firstly, thank you for taking the time to respond. I really appreciate it.

I'll give that a try; would 3m be okay? Is there particular brand you recommend?

Thanks
 

Dodgexander

Moderator
For HDMI 2.1 signals 3m may even be too much. I have a 3m cable for HDMI 2.0 and remember at the time researching that it wasn't wise to go bigger. Since its just for testing I'd just get the cheapest 2.1 cable with certification you can. You may even be fine with a non-certified model.
 

GhostOfJericho

Novice Member
For HDMI 2.1 signals 3m may even be too much. I have a 3m cable for HDMI 2.0 and remember at the time researching that it wasn't wise to go bigger. Since its just for testing I'd just get the cheapest 2.1 cable with certification you can. You may even be fine with a non-certified model.
Okay thanks.
I'll report back with my findings, it may take a few days.

Thanks!
 

GhostOfJericho

Novice Member
For HDMI 2.1 signals 3m may even be too much. I have a 3m cable for HDMI 2.0 and remember at the time researching that it wasn't wise to go bigger. Since its just for testing I'd just get the cheapest 2.1 cable with certification you can. You may even be fine with a non-certified model.
Hi mate, hope you're having a good weekend.

Okay so, I purchased a 2m certified HDMI 2.1 cable; no problems whatsoever, even when quitting a game. It worked flawlessly. With this in mind, my 5m cable did have problems. Unfortunately, I can't keep my PC closer than 5m away long term. What would be your recommendation? Is this a limitation of the TV itself?
 
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next010

Distinguished Member
Microsoft appear to have their own certification program for Xbox, this 10m HDMI 2.1 cable has Xbox certification, no idea is that really holds up but also not sure if its possible to get that cable from UK.

I assume you have already tried chroma subsampling 8-bit YCC 422 SDR to reduce bandwidth, if that made no difference then not a whole lot of other options, there are HDMI over ethernet extenders but these are plain 4K 60hz HDMI 2.0 only.

RGB 444 HDR 10-bit 4k 120hz G-Sync needs direct cable connection.
 

GhostOfJericho

Novice Member
Microsoft appear to have their own certification program for Xbox, this 10m HDMI 2.1 cable has Xbox certification, no idea is that really holds up but also not sure if its possible to get that cable from UK.

I assume you have already tried chroma subsampling 8-bit YCC 422 SDR to reduce bandwidth, if that made no difference then not a whole lot of other options, there are HDMI over ethernet extenders but these are plain 4K 60hz HDMI 2.0 only.

RGB 444 HDR 10-bit 4k 120hz G-Sync needs direct cable connection.
Hi mate,

Thanks for the reply. I have tried reducing bandwidth by changing those settings yes.

I am able to buy the Cable Matters HDMI 2.1 cable here in the UK; a fair price too.
So, 5m is the minimum, with 10m being ideal, as it can run around the skirting and get the "girlfriend" approval. 5m stretches under a bed with access to storage boxes being trickier as a result.

The 10m is only £15 more than the 5m. Would it be a much safer bet to go with the 5m? If you believe so, I'll pull the trigger right now.

Thanks for the help mate
 

next010

Distinguished Member
10m is what you really want, if it doesn't work maybe you can sell it somewhere else to get some money back and try the 5m, so go with 10m I guess but cant say with any certainty it will work.
 

Dodgexander

Moderator
I thought it may help your issue. Sadly there's not really a steadfast answer regarding cable size. 10m seems to be the max for HDMI 1.4...with HDMI 2.0 I think its around 3m before you start to see issues and with HDMI 2.1 probably even shorter.

Sadly there also doesn't seem to be any HDMI 2.1 powered senders/receivers on the market yet, because usually that would be the obvious thing to suggest.

Perhaps think about remote gaming via your home network and an Nvidia shield?

Maybe what you could do (if you have the outlay) is make a shortlist of cables you think may work, and try each one, then return them if they don't work. I personally think this will be wasting your time unless you can somehow move the computer within 3m from the PC though, I think you'll be fighting a losing battle :(
 

GhostOfJericho

Novice Member
I thought it may help your issue. Sadly there's not really a steadfast answer regarding cable size. 10m seems to be the max for HDMI 1.4...with HDMI 2.0 I think its around 3m before you start to see issues and with HDMI 2.1 probably even shorter.

Sadly there also doesn't seem to be any HDMI 2.1 powered senders/receivers on the market yet, because usually that would be the obvious thing to suggest.

Perhaps think about remote gaming via your home network and an Nvidia shield?

Maybe what you could do (if you have the outlay) is make a shortlist of cables you think may work, and try each one, then return them if they don't work. I personally think this will be wasting your time unless you can somehow move the computer within 3m from the PC though, I think you'll be fighting a losing battle :(
Hi mate,

Yeah, I bought the 10m Cable Matters cable, still the same thing unfortunately. It's bizzare, I'm guessing these cables are working for some people, else the product wouldn't exist surely? Do the TV's themselves vary in reliability? Is this something John Lewis could help with do you think?

Somewhere between 2m and 5m seems to be my sweetspot 😔. I'm going to return (if they let me) both the Ruipro and Cable Matters cables.

Funny enough I used to gamestream using Moonlight on the old Nvidia shield TV. Unfortunately, not the greatest of experiences in regards to signal quality and refresh rate/G-sync.

I'll have a rethink about distances, move some furniture around; hopefully not get in trouble with the girlfriend 🤣.

Thank you both again for taking the time to help me. It really means a lot; especially after so much frustration and time spent troubleshooting.
Maybe I can get the Cable Matters 5m cable working, as it'll still be AOC compared to my previous 5m cable.

Thanks again!
-Grant
 

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