SOLVED
Bit of a long shot here because this is one of those issues where I search for the problem and you get a sea of replies like "have you checked the settings?" or "have you tried changing HDMI cables".

I just got a brand new LG OLED TV and I'm happy, but I've been watching Arcane on it and I notice jarring changes in brightness through the episode.
I'm playing through a native app (Stremio) on WebOS and it's not the source file, I've tested the same file on two different monitors and it's fine.
I went through the settings and disabled every autocorrect and "boost" capability the TV has to try and diagnose it, and the first pass did seem to improve the rate of changes, but it still happens maybe once every 5 mins of watch time.
From what I can tell it seems to be picking up particular colour/brightness changes in the source (Arcane is full of then being so vivid) and when it does, it just changes the brightness of the whole display.
I'm no expert here, I'm also colour blind, so I won't categorically claim it is definitely brightness changing, it could be contract or colour, I'm not sure, but it looks like brightness because the whole picture gets darker or lighter.

I wondered if it was actually flip flopping between SDR and HDR which honestly, it might be. If it is I have no idea how to fix that, as the TV seems to have no option to enable or disable HDR on native apps.

Any advice, thoughts, things to try would be appreciated. I'm technically orientated but I don't really know much about changing picture settings to be honest, I tend to pick the most basic/neutral setting and leave it like that.

Edit: I've dug out the old 4k firestick as suggested and don't get the flickering at all through that. Also running through the guide below helped make the picture look even better! Thanks everyone!
I might yet grab the service remote though and see if I can make the native apps work, then I can retire the firestick for good.

Hi Tildestrians! I recently acquired a broken Sony TV from work. Its older, but its 4K, and would be a substantial upgrade over my current TV, so I am hoping to fix it. My usual willingness to tinker and google prowess has failed me. I am hoping one of you can provide some guidance.

Its a Sony XBR-55X850B. It is showing an error code of 7 flashing red lights. I tracked down the service manual (Sony, you should really have this available to customers and not locked behind an "authorized service center" certification), and it says the motherboard needs to be replaced. I found a replacement motherboard on ebay (it was for the 65 inch version, but that should not make a difference). I installed, and it gave a different error code. I think it was flashing green and orange. Based on my research, that means it needs new firmware to be flashed. Sony's website doesn't still have the firmware file for that TV (should be illegal in my opinion), and tells you to contact support. Support seemingly can't give out the firmware file either. I found a firmware file on Softpedia, but I have no idea if it is legitimate or even still a working file. Threw that on a fat32 drive, and couldn't manage to get it to update. I tried multiple drives and all usb ports over the course of 2 weeks. I ended up pulling the new motherboard and returning it (thankfully I was able to return it for full price). Now I am stuck with a TV panel that works perfectly, except for the motherboard, and I seemingly can't replace the motherboard.

This got me thinking: I don't need anything fancy. I want a display with an HDMI input that takes 4K signal and puts it on the screen. I truly don't need anything more than that. Even an IR remote for power is optional, because I could plug it into a smart outlet. I don't need the speakers because I have a receiver. I know you can get bypass boards to turn laptop screens into monitors. They take the place of the support circuitry on the laptop motherboard and give you a display input, and nothing more. Is there anything like that I can get for this TV? I don't know where to start on that search.

Or are there any other routes I should explore before junking this TV? It feels really bad to throw out a perfectly good 4k panel just because the motherboard is broken.

I recently visited my sister who has a big screen TV that shows very smooth movement including on Star Trek, the original series. Not that I don't have smooth movement on my home TV set, but hers was ridiculous. It almost looks like raw footage before it was refined down. It was like there were frames between the frames, if that makes any sense.

What am I seeing here?

I'm wondering if anyone here might be able to help me with this.

We've bought a Amazon Echo Dot for my Grandma who's no longer able to see very well. The idea was to connect it to her Smart TV so that she would be able to navigate it using voice commands rather than the remote (which she can't see).

I've been able to add the TV as a device on the Alexa app, however I'm unable to get Alexa to carry out any commands on the TV - change the channel, open an app etc.

I believe that what I need to do is connect the TV to the Echo Dot via Bluetooth. Is this correct? Is it functionally a different thing than having something as a device in the app? Currently when I go to the TV under devices and click to manage linked Alexa devices, the Echo Dot is greyed out because it's already paired with a device (presumably the iPad where I've downloaded the app as there are no other devices connected).

If the lack of bluetooth connection is the issue, I'll need to buy a Bluetooth transmitter for the TV has it doesn't have bluetooth capability. So I just wanted to see if anyone had any advice for me before I invest in another piece of tech.

So I rescued an old TV from the trash, appears to be a Hitachi Rear Projection TV, no obvious model number available, and when I try to power it on, it will display just fine, but it has no audio coming out UNLESS I turn it over to antenna input, in which case it has bone rattling analog static. This is the US where everyone changed over to digital television, so not super helpful, and while I could do some sound splitting magic, that seems like a waste if there are already good speakers. So I have come to you, honored Tildos, for assistance in pointing me in the right direction on whether or not this television's speakers can be saved.

EDIT: This is now solved thanks to @Amarok! Solution is here. Changing the refresh rate from 60 Hz to 120 Hz fixed it.

My husband and I recently upgraded our TV to a Samsung Q70, and I have started experiencing an odd issue, visible in this video here.

The Issue

There's a horizontal section across the entire bottom of the screen that seems to be refreshing later than the rest of the TV. The game is running on a PC hooked up to the TV via HDMI, and the TV is running on game mode. This issue did not happen on our last TV (a 10-year-old Visio that I don't remember the model number of).

The Oddness

• It doesn't happen on the desktop or in video inputs.

We've been watching YouTube and Hulu through a Shield TV that we also have hooked up, and this issue isn't present in any of those, nor is it visible when I'm using desktop applications on the TV through the PC.

• It only happens in certain games.

The video is from Trackmania 2: Lagoon, where it is always present. Meanwhile, it is not present at all in Trackmania (2020). Likewise, I've been playing 428 Shibuya Scramble where it shows up in the exact same way in the exact same area, but it does not exist in Distance or Rogue Legacy, for example.

• It does not respond to v-sync.

I've tried toggling v-sync on and off, both through the game itself and forcing it through my video card. Neither alleviated the issue. The display looked the same whether or not v-sync was turned on or off.

I'm looking for any guidance anyone can give me, especially if this is a hardware issue with the TV itself, since I'm still in the return window.

I've been lamenting the death of the dumb TV for years now, but I'm finally in the market for a new set and trying to plan my next purchase carefully.

I've come to grips with the fact that any late-model TV I buy is going to feature some or all of the following:

• Internet connectivity
• Slow, janky menu screens with awful UIs
• Pre-installed apps (all of which I consider bloatware)
• Ads incorporated into the built-in menus or overlaid on my content
• Alexa / Google Home integration
• Automatic content recognition and/or other data collection techniques
• Microphones or cameras, purportedly for voice/gesture control

My goal is to take a stock smart TV and completely neuter all of the above, resulting in an otherwise fully functional dumb TV. All of my content will be delivered over HDMI from external devices.

As I understand it, basically all modern TVs are running one of five operating systems: Android TV, webOS, Tizen, Roku TV, or SmartCast. Not knowing anything about these platforms, where should I begin? Which are most susceptible to rooting? Are there any good custom ROMs I could install that would achieve what I'm looking for? Surely others have asked these same questions before me, but I can't find the answers online.

Yes, this is a companion post to my other home theater question earlier today.