Thanks for the reply.
In comparison, I have found my laptop's CPU maximum or 'throttle temperature' to be 90C, and for hdmi adapters available online (and I suspect also any port on a tv), their maximum working temperature is suggested to be around 85C. There is no recommended working CPU temperature in the stick's manual. The NowTV Roku stick temperature from within it's hidden menu has a visual indicating safety. The top of the page shows someone else's example. For my own, 80C is in light orange after switch on, just over two thirds of the way along the bar, which seems to indicate a maximum allowed temperature of set of around 120C before any built-in temperature warning would kick in. After use, 100C is in dark orange but still not quite near the end. Perhaps the temperature is incorrect, but the bar is not..
High cpu readings seem to apply to most tv sticks judging by user comments, regardless of manufacturer. This is one reason I didn't think of the reading as suspect. Surely a simple software update could fix these readings, if the sensors were all off slightly? Users claim their devices no longer work as they should after they stream for a certain length of time. Perhaps this is their internet cutting off often, due to a poor signal. Reverting back to the menu mid-play might also be a software bug.
A stress test for the first competitor Fire tv stick can also be found online, which sees it climb to 200F after a few minutes (just over 90C):
Another reason I didn't question the reading is that there are one or two reports of similar devices ruining televisions, despite not always using the tv usb port for power. However, due to the lack of similar complaints, I'm not sure if this is just coincidence and bad tvs, or just suspect posts.
I did have the device initially plugged in to the usb port, but as you suggest I've swapped to the adapter, because turning off the television would no longer equal the stick switching off. I'll keep it on idle and watch that temperature. The device should switch off after four hours of being idle, I'm still not completely percent convinced over the readings being way off the mark. The companies themselves don't seem to want to give details over temperature, and roku themselves giving away free hdmi extenders on their page that covers the device overheating, doesn't really give confidence. There is no ventilation on the stick itself either. Judging by some forums and youtube videos, users have gone as far as to drill holes to reduce readings, and even added heatsinks. (edit- sorry, just noticed the extra posts)
I think I will eventually switch to a box with a fan, but I'll have to look around online to see what fares best in similar stress tests.
* last ever edit - upon start up, the stick starts at 54C, and on idle climbs up to around 85C. This is the same, regardless as to whether the tv has been on for a long time or not (always using the stick's power supply). It takes around 10 minutes to get to 85C. Watching videos, it goes over 100C as noted before. I suspect it has no dedicated graphics chip on board. I can still use the NowTV player on the laptop for the service, but I don't think I'm going to be chancing these sticks with any television. Roku also seem to make televisions, of which I've noticed one user to be complaining about overheating. There seems to be a common issue here.
ps for anyone with a similar device, this stick is a NowTV Roku model 3801 from last year, v568.13E04185A, with the latest 20181221 update, running on 5V 1A. On idle in the stats menu, it seems to fluctuate between 216mHz and 1000mHz occasionally (probably not important). Thanks for all your replies
Last edited by Ace on 27 April 2019 3:32pm - 3 times in total