Blinking issue on LG B1 HDMI 2.1

mariusbo

Novice Member
Hello.

So I have this issue on my B1 where the picture disappears for 1-2 seconds. Video of the issue here:

This happens on both HDMI 2.1 ports. Doesn't matter if I game using my PC ([email protected]), or hook up my Nvidia Shield TV or set-top box (for the record, these are plugged into the other 2 HDMI ports now, so the issue is not present there).

What I have tried:
Different HDMI cables. Both cheap, and somewhat expensive. I have also tried a fiber optic cable.
Turning down to 100hz on my PC.
Switching off HDR.
Fabric reset of the TV.
Update the software (currently running latest 03.21.00)

Nothing seems to help. So the question is, does anybody else have this issue? Can't seem to find anything on this issue. Should I RMA it? Thanks!
 

Joe Fernand

Distinguished Member
AVForums Sponsor
Have you tried a different Source connected to the HDMI Inputs on the TV?

Joe
 

mariusbo

Novice Member
Yeah, I have tried an Apple TV and Shield TV on both HDMI 3 and 4 (both are HDMI 2.1 ports). I believe game mode kicks in on both devices. And the problem exists here as well. But when plugging these devices into HDMI port 1 and 2 (which are HDMI 2.0), the problem goes away.
I suspect the problem is in the game mode (or some of the gaming features like gsync). However, I bought this TV to game on, so kinda useless to not have a working game mode :)

I am however in contact with LG, so will wait and see what they say.
 

TheCotters85

Novice Member
Hello.

So I have this issue on my B1 where the picture disappears for 1-2 seconds. Video of the issue here:

This happens on both HDMI 2.1 ports. Doesn't matter if I game using my PC ([email protected]), or hook up my Nvidia Shield TV or set-top box (for the record, these are plugged into the other 2 HDMI ports now, so the issue is not present there).

What I have tried:
Different HDMI cables. Both cheap, and somewhat expensive. I have also tried a fiber optic cable.
Turning down to 100hz on my PC.
Switching off HDR.
Fabric reset of the TV.
Update the software (currently running latest 03.21.00)

Nothing seems to help. So the question is, does anybody else have this issue? Can't seem to find anything on this issue. Should I RMA it? Thanks!

I have a very similar issue also with my B1! When I boot up my PS5 the screen blinks for a few moments as if the cable is loose, then sometimes goes black with HDR appearing in the corner. Like you this is on HDMI 4. I have swapped cables but still have the issue. I raised a query with LG a couple of days ago so will await the outcome. Have you had a reply to your query with them?
 

mariusbo

Novice Member
Hello. Yeah, so i did talk to LG. I scheduled an appointment for them to come home to me and have a look. But in the meantime i figured out something. I had foolishly placed a WiFi-router right behind the tv. When i moved that, the problem disappeared. Well, not entirely, but to the point that I can have an entire session without the problem. So I talked to support again and canceled the appointment because I was afraid they wouldn't get the problem when they were here. But I made an agreement that I would schedule a new appointment if it got worse.
 

TheCotters85

Novice Member
Hello. Yeah, so i did talk to LG. I scheduled an appointment for them to come home to me and have a look. But in the meantime i figured out something. I had foolishly placed a WiFi-router right behind the tv. When i moved that, the problem disappeared. Well, not entirely, but to the point that I can have an entire session without the problem. So I talked to support again and canceled the appointment because I was afraid they wouldn't get the problem when they were here. But I made an agreement that I would schedule a new appointment if it got worse.
Ah fingers crossed. I too have my router behind the TV. About a foot behind it. Problem is I can't move it as its in the best location for me. I will see what LG come back with. Thanks for the reply!
 

fluxedman

Well-known Member
HDMI 2.1 imo is more stressful both in hardware requirements and compatibility, so its tricky to diagnose such issues.

But easiest way to see if there is a fault imo is try 2-3 approved hdmi 2.1 certified cables
(with Certified hologram stickers), try and use the shortest and thickest ones if you can.

Even like these:
Kenable hdmi 2.1 cable

If you still get the blinking issue, try another device (pc, shield, cable/sat box etc) on that same hdmi and if it still blinks then its unlikely to be the source device and the TV at fault.

HDMI ports can go iffy and the blinking fault is a common hdmi port failure symptom, but it can also be a firmware/software or compatibility glitch. So it is a tad tricky to diagnose it.

Obviously if you were for example to reset the TV to factory settings, try 3-4 devices on that problematic hdmi 2.1 port and it still blinks then its the port to blame imo, then really it needs to be booked in for a new TV mainboard with LG.

Router behind the TV should not really make any difference imo.... but sure stranger things can occur, its trial and error.
 

dbMdb

Novice Member
Hello,

I'm having the exact same issue here on my brand new B1.

The issue appeared a couple of times after testing games and having Game Optimizer enabled.
In Game Optimizer menu, i noticed both Low Latency and VRR flashing ON>OFF.

When Game Optimizer was turned off, the issue persisted and the Picture Mode was continuously switching between 2 modes (can't remember exactly which ones).

The issue disapears when i turn off & on the tv.

Relevant Specs:
Windows 10 Pro 21H2
RTX 3070 4K @120Hz 10-bit HDR, G-Sync enabled for fullscreen mode only
LG B1 running on latest firmware (03.21.00)
Cheap HDMI 2.1 8K certified cable
 

dbMdb

Novice Member
Im still experiencing this really annoying issue.
Sometimes i even get a No Signal from the HDMI.

I've managed to narrow it down now.

Disabling Gsync in Nvidia control panel seems to solve this issue.
While this is a solution, it's far from ideal.
One of the main reasons i bought this TV was because of the G-Sync and VRR functionality!

Im running on latests Nvidia drivers (511.65)
 

spikecast

Well-known Member
No way I'd be putting up with that, hardware or software issue. Get it replaced and if it's still the same I'd be looking at getting another TV. Never had this issue on our CX or C1. I know the B1 uses different components so could be that.
 

dbMdb

Novice Member
Ok, well it seems i might have jumped the boat too fast with my posts here and my workarounds/solutions.

Seems like Gsync/HDR/4K/120Hz is really pushing the limits of Hdmi connectors and cables.

Fiddling with my (90°...) connector seems to have helped the most with this issue.
I didnt get any issues yesterday while using Gsync & VRR.

I never expected hdmi 2.1 to be so sensitive.

Im curious how stable this will be when i actually push this even further and send Dolby Atmos or PCM 5.1 over that same cable...

Is there any way of calculating/seeing how much bandwidth im currently using?
 

fluxedman

Well-known Member
Ok, well it seems i might have jumped the boat too fast with my posts here and my workarounds/solutions.

Seems like Gsync/HDR/4K/120Hz is really pushing the limits of Hdmi connectors and cables.

Fiddling with my (90°...) connector seems to have helped the most with this issue.
I didnt get any issues yesterday while using Gsync & VRR.

I never expected hdmi 2.1 to be so sensitive.

Im curious how stable this will be when i actually push this even further and send Dolby Atmos or PCM 5.1 over that same cable...

Is there any way of calculating/seeing how much bandwidth im currently using?

Think it was mashing the green button on LG oleds, try it? some post here might assist on working out the hdmi bandwidth also:



do you use an 90 degree angle hdmi cable? there apparently not the best when it comes to meeting hdmi specification or reliability sadly, actually a guy on Avsforums sister site who reviews hdmi cables once said to avoid them all together.

Its always tricky, I once had to try 7 hdmi cables to get 4K 60hertz on my Samsung TV to work, the most expensive ones all failed yet the shortest, thickest hdmi cable that did work cost £1 from poundland.
 

TheCotters85

Novice Member
Yeah, I have tried 3 different cables (and different devices). I now use a 2 meter long Belkin cable (Belkin Ultra High Speed HDMI 2.1 kabel (2 m)). The moving of the router did help, but the problem didn't go away completely. So yeah, I wonder if I just should schedule a new serviceappointment.
Hi, I got my TV back from Currys (here in the UK) repair and they could not find any issue with my HDMI port 4 believe it or not and they told me they had a PS5 running for a good few hours, I sent them the video of the issue I had but sods law they could not replicate it. They changed the main board just in case.

My point is, I tried everything, new cable, factory reset of both devices but the issue was still there..... What I DID NOT try was a power cycle. Where you completely power down and unplug the OLED from the wall and leave it a good while and then try again. I googled it and this can sort a lot of issues out, this COULD also explain the fact Currys could not find an issue as the TV was obviously completely powered down for it be taken away.

I got the TV back this morning and only very quickly tried it as I had work so fingers crossed the issues is resolved. Will test it tonight and first thing tomorrow morning.

So, Have you tried a power cycle?
 

dbMdb

Novice Member
Well i still didnt solve the issue on my end. I replaced my 90° hdmi cable with anorher 'old' hdmi 2.1 cable i had, but had the same issue there.
I found tons of posts over the internet with the same issue we have and tried a lot of the solutions but to no avail yet.

I just ordered a certified hdmi 2.1 cable now. We'll see how it goes.

Looked up the cables i had, and lots of reviews start to pop up, complaining about the same issues we're experiencing.

Too bad i bought those 'old' hdmi 2.1 cables last year, thinking i'd be future proof. I cant get refunded that easily now - if at all.
 

fluxedman

Well-known Member
hdmi cables can be a nightmare, certified or un-certified sometimes. I once tried over 12 hdmi cables once to fix my 60hertz @ 4K issue before finding one that worked (Ibrah brand orange).

The certification is not 100% an guarantee it will work but its as best as they can do, still you would know if its an hdmi cable issue if you lower or switch off a setting and it fixes it ie reducing resolution from 4k to 1080p or HDR on and then off etc

Once you find a cable that works.... buy 2 if its cheap and bookmark it
 

dbMdb

Novice Member
Gah, this is driving me nuts.
New cable does not help.

If anything, the issue seems even worse now.
I could make flashing disappear by either turning off HDR or turning off Gsync.
This would provoke a new handshake and then it would work again.

Now with both turned off i'm still getting blinking issue. - edit with at 100Hz now...

How are things for you Cotters, with the power cycle?
 

dbMdb

Novice Member
Well... im glad i finally found the source of my sporadic issues!

It wasnt the fault of my 'bad' hdmi cable.
It was simply some interference from a bad audio cable i was using!

So for anyone with similar issues:
  • Check all cabling of all electronic appliances that run near your hdmi cable.
  • Move the wifi router further away.
  • If you use bad cabling somewhere, consider some ferrite block to shield them (not on the hdmi though!)
 

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