Solving playback issues

[mikew_nt]

@MrEd see my post above.  I did extensive re-padding of the thermal pads, as well as addition of a significant heat sink that extends out of a hole in the case.  Even with all that, I still get the warning once per night.

Based on the relatively cool temp of the heatsink, my suspicion is the warning threshold is probably set too low in the Roku software. 

But, without access to the code, the change logs and the thermal characterization measurements on the 4670, there's no way for me to tell.

But this should be relatively simple for Roku to investigate and determine the issue, I'm not sure what the holdup is here.

[Montclairat]

I'm really grateful for the insights & advice from this community on how to improve the Ruku. Two of my Ultra units tend to overheat regularly- its becoming more frequent. I’m a bit concerned about the liability of opening & modifying them. What happens if they start a fire?  

[MrEd]

The thermal past located under the shield may also need replacing.

CAUTION: Aggressively removing the shield will cause permanent damage.

[mikew_nt]

@MrEd are you talking about the plate on the bottom?

That was not coupled to the circuit board, and there is no point in coupling it to the plastic case.

Here are photos to go with my text description in my post above.

I worked for a fanless PC company, I know what I'm doing.  I literally could not do more to heat sink this thing.

Also, everyone's worked fine until the June s/w update.  It's not like everyone's thermal pads went bad all at the same time (and mine looked just fine).

I'll get an IR gun on my heatsink tonight and let you all know how warm it is running, but it is only moderately warm under load, and that tells me Roku has a s/w issue, and probably has the overheating warning threshold set incorrectly.

[Gatorgogo]

I just put something under my Roku Ultra (4670X) to let air get all around it.  So far, no overheating messages.

The other thing I tried was to swap out the Roku Ultra with a later model.  Unfortunately,  I ran into another mystery that Roku has not solved either.  When I try to use the newer Roku Ultra (4802X) or the Roku Ultra LT (4801RW) both cause the ARC/CEC HDMI connection to the soundbar to disconnect and I don't get anything out my soundbar.  There has been lot's of discussion on this problem too but solutions are mostly  finger pointing - is it the TV or the Roku. 

So for now,  I just put back the Roku Ultra 4670X and propped it up to keep it cooler and the soundbar works.  

[mikew_nt]

OK, I got out my IR temp gun, and also accessed the secret menu.

At idle, my heat sink (see my previous posts) is warm, about 45C.  Secret menu reports CPU temp at 93C.

After 30 minutes of 4K Hulu,  my heat sink (see my previous posts) is virtually unchanged, warm, about 45C.  Secret menu reports CPU temp at 98C.

These secret menu CPU temps are consistent with what other people have reported seeing.

I did not get an overheating warning, but I generally only get one per night, they are not that frequent.

So, I'll leave this here for others that might know this area better.

Based on my experience working for the fanless PC company, I would NEVER expect to see a 45C+ delta between the CPU temp and the heatsink temp.  Like, never.  Ever. 

I cannot explain that delta, except that either the secret menu temp is wrong, or the CPU is not effectively shedding heat to the heatsink.  If the temps are correct, and it's the latter, then something is seriously wrong with the CPU design.

It's possible that following the June s/w update Roku is running these devices a little hotter, but my theory is that there's a software bug elsewhere that they need to find.

I'm still leaning toward this being a bug around the threshold temp for the overheating warning, and/or bugs in reading the CPU temp.

[sickyd]

Just experienced the overheating warning for myself for the first time tonight and Google brought me immediately to this thread. The fact so many of us are experiencing all at once does make me think it is a software issue that was recently introduced. The temp level that triggers these warnings must have been lowered in the software or they introduced new background processes that keep the processor running at full load like crazy (probably advertising!). Even at idle on the main screen my unit (4670RW) is running at over 100C consistently. 

[yams1290]

Same issue that has been recurrent and unpredictable for the last few months.  Talking to Roku customer service has not helped.  My unit is also propped up on its side, away from everything.  I wonder too if this is a software issue.  Hopefully something Roku can resolve with an update?

[drgteye]

Given the history of this thread, they won't do anything. They don't care about their customers - they just want money and will say we need to buy a new one because ours is out of warranty. (Go ahead Roku, prove me wrong).

I'm about ready to open mine up, remove the thermal pad/paste/heat sinks and redo it. I build my own computers - thermal paste dries out and loses its ability to transfer heat away from circuit boards/components. So perhaps that'll help.

All I know is when my Roku dies, I will not be getting another one. 

[mikew_nt]

@drgteye see my posts and pictures above.

This is what I used

https://www.amazon.com/gp/product/B08CMR9MZZ/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1

https://www.amazon.com/gp/product/B096ZNHY8F/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

I cannot possibly explain the huge delta of actual measured temp on the heatsink (it's only moderately warm to touch, so my IR gun is measuring accurately) and the reported internal CPU temp.  It's simply not possible unless there is something very, very wrong.  Which there probably is.

My assumption at this point is that this is a software bug around temp sensing or warning threshold setting, or possibly just a really bad chip design that is not properly dispersing heat into the heat sinks.

My mods got me down to maybe one warning per night, but there's not way with the amount of heat sinking I did that this should occur.

It might have been borderline before the June s/w update, and that update just pushed it over the edge.

If I had access to the s/w code and the hardware characterization reports, I could probably figure it out, but this is going to have to be in Roku's hands.  I wish Roku would embrace the help, this is a great community with some pretty experienced people, and this doesn't feel like one that we couldn't solve as a team.