Roku Ultra (model 4660x) serial number: YJ002E183987, build 8.0.0 build 3138-46, device ID: CK3792183987

Sony XBR75X940E, Anthem MRX720, Sony UBPX1000. X1000 works flawlessly as do sources other than the Roku. All sources hard-wired to the internet @ 300mb/s.

I have two situations.
1. If the screen is stable after a reboot, it usually flashes a couple of times during Netflix/Amazon playback of any resolution then plays on fine.

2. After a couple of days it will loose this and start flashing from the moment I switch inputs. I’ve tried rebooting inside the menus and that didn’t work, I’ve looked at my advanced settings and it’s set to 4.2.0 subsampling, so I’m baffled.

I’ve tried other suggestions, rebooting the tv, receiver, etc. nothing works but a hard reboot at this point.

Until this gets sorted out, I’ve got it now set to 1080p. Will test this way for a couple of days.

What does the auto-adjust display refresh rate under advanced display setting do? Wondering if this will sent things native and let the display scale the video?

I just noticed a software update: Software Version: 8.0.1, Build 4018-46.

So, I (rebooted), unplugged the Roku.  It came up.  I switched it to 4k60, it passed the test.  I went to Netflix and the screen started to flicker.  I exited Netflix, and the flickering remains. It seems that the flickering in immediate now.  Something definitely changed.  

I again dropped the resolution down to 1080p, it played fine.  Please tell me what I can provide to help solve this problem.  Please keep trying to fix it!

I have also noticed an apparent transient glitch in the Netflix App. One time I launch App I see 4K content banner, then sometimes I launch App the content is not visible.  The remedy I've found is to log out of Netflix and re-log in and it returns.  Not sure what is causing this, but the App needs some work still -hopefully with time this will work itself out.  In the past I've been able to find 4k without the banner and it played fine, it seems that it's something related to the login.

Status update: very ODD.

So, I was out and just came home a few hours later and the Roku was off/locked up, no indicator light of any sort.  It's all on a UPS power supply, so it didn't just not get power.  Any suggestions as to why the player would shut down/lock up?  It is in a rack system, and it is right next to the fan/system and sitting on top of the UDPX1000 Sony (which is usually off, and has been during this whole ordeal).  Is it possible it overheated?  It followed closely a software reboot from earlier that had quite a bit of time trying to sync at 4k 4:2:2.  Once sync'd, aside from loosing power or whatever happened, it seems to stay stable.  Haven't seen an HDCP error in 4:2:2.

I've tried switching back to 4:2:0 and all the screen does is flicker so bad I can't necessarily change it to another resolution such as 1080p, which has been stable.

Please advise!  I am beyond out of ideas.

As a side issue, I had a Roku3 on top of an OPPO that got real hot, but I never experienced a shutdown of any sort with it in the same rack.  This whole things is bazaar to me.

Up time since hard reboot (power plug) over 3 hours and not one glitch.  If it is overheating it was doing it while nothing was going on.  So, I'm thinking heat was not the issue since it locked up/was unresponsive/no video while it sat idle with the entire rest of the system OFF.

I had a response from a user on AVSForum that said when it's in screen saver the light is off.  Is this true?  If not, other than no power, when does the light possibly go off?

Tbaudoin wrote:

I had a response from a user on AVSForum that said when it's in screen saver the light is off.  Is this true?  If not, other than no power, when does the light possibly go off?

Yes, the light goes off when the screen saver is active. Other than that, it will flash as it's booting or if it can't connect to your network (or there's some other problem) and it will flash when you press a button on the remote. Otherwise, it will only go off when the screen saver activates or you remove the power.

-JT

Thanks for your help. Getting to know all the ins and outs. Thanks. Hopefully things will sort out eventually.

Sometimes my Roku remote loses connection with the Roku and so if it is in sleep/screensaver mode, then pushing any button won't bring it out of this mode. I pull the batteries then put them back in and it is fine again. I have seen others complain of this as well. Maybe this is what happened and when you rebooted it, the remote connected again. 
Did you actually turn the tv on to the input the Roku was connected to and not see any picture on screen or did you just see that the Roku had no light on which is normal?

Absolutely no picture, now coming to realize the light is normal.  So, I don't use the Roku remote.  I'm going through a control4 system.  It works the same, except it relays from it's brain to the system for controls.

Anyway, I really appreciate all the clarifications and suggestions.. Glad to know feel like I'm the only one with issues...

Latest Status:  The Roku Ultra is up and running, no hitches except Netflix randomly loosing the 4kUltra banner.  I have to log out of Netflix and log back in -then it returns until?  can be days before it happens again. 

On the setup: Roku Ultra -> Anthem MRX720 ->Sony XBR75X940E.  All controlled by Control4 remote IP/wifi control.  The trick to my NOT having flickering was to set the Roku to output 4:2:2 chroma.  4:2:0 causes unrecoverable issues where I have to hard boot the Ultra to get it back.  Anyway, hope this helps someone.

Regards,
Terry.

I had a similar issue but mine was letting the TV try to switch refresh rates in the advance picture setting. I just wanted to test it since the Roku is probably better at handling it than the TV so leaving it off was my intention anyway.

My understanding is that 4.2.0 is going to be visually indistinguishable from 4.2.2 so to get the best bandwidth just leave it on the 0 setting. In theory 2 has more data.

Yea, I'm wise to needing the input set to accept "Enhanced" signal.  It supports 4K60 4:2:0, 10bit 4:2:2 & 4:4:4.  Not sure why it freaks out my display set to 4:2:0, but as long as I'm not having streaming and connectivity issues, I'm really grateful.  finger's crossed.  Big Shoutout to Rtings.com for their review of the Sony.  It's good information.

UPDATE:  4:2:2 was definitely my solution.  8 days and many hours of streaming later.  It's been solid.  Only the netflix app issue remains.  Today I deleted the app and reinstalled it.  Maybe this will solve it.  Dunno, but very grateful for the 4:2:2 setting. 

I just bought a brand new TV yesterday and I was getting the screen flicker on Netflix when in 4k. I tried all the different settings I could, and even went online to buy new cables. But this 4:2:0 vs 4:2:2 sub-sampling did the trick! No more flicker when I bounce in and out of Netflix. Thank you!