@SpaceWar - The metal trivet may have been creating interference.
I had to relocate my unit and before doing that decided to do a quick test. Using the IR thermometer I measured the temperature of the bottom and the hottest spot was running at a measured 44 deg C (box was idling). Put it on its side and the temperature dropped to 39 deg C within minutes.
@4WheelSpyder - do you think that placing the Tablo upside down will have the same beneficial effect?
I have a Tablo 4-tuner device and measure ~55C when all 4 tuners are fired up. Everything is working perfectly fine but the device is still very hot, in fact too hot to touch the base plate for more than a second.I'm wondering how you got approval from the appropriate US governmental agencies for something that could be considered a health hazard. I'm sure you guys did everything right but would you mind pointing us users to the regulatory approval document you got? This would be a more satisfactory answer than what I've seen from @TabloSupport so far.
While they may (or may not) function normally, there must be a QC control issue with the 4 tuner Tablo as too many people report their units generating excessive heat. Despite provided response, a normal 4 tuner Tablo is warm to touch and not scorching. If I received a unit that was anything other than what I have now, it would be returned as defective.
i’m not perfectly certain, but my experience with another OTV device tells me that the (excessive) heat source is not the cpu, but the HDTV tuner module. with this other device, the the coaxial connection point is too hot to touch but for a couple of seconds. beyond that, it would actually burn your fingers.
if the heat plate is at the bottom of the unit, you may get better heat dissipation placing it upside down. there are no moving parts, so this should be ok.
@rem736 The hottest point should be the heat shield - which is located directly under the blue LED on the front of the unit. The coaxial input can get pretty warm too, though.
Some folks have proposed that placing the unit sideways or upside has resulted in more stability. While it’s certainly possible, we haven’t been able to see that kind of behaviour in our testing here.
I know I was one saying sideways made a huge difference in issues. But I am also afraid to go back to laying down to see if it is still an issue 
The wonderful friendly Canadians decided to send us - to share with us - some of their cool air so it’s hard to judge right now, but if that wasn’t part of the equation I’ve noted that our quad doesn’t really run all that hot. I watched some live TV using Tablo last night, the temp in the house was 67-68 degrees F and the Tablo wasn’t all that hot. Warm, yeah like other electronics, but all-in-all, cooler than SOME of my electronics. It was no warmer than my notebook which has active cooling. I figure if it does seen to get warmer than I am comfortable with I will try making an aluminum stand, powder coating it for looks and setting it up on edge but slightly elevated as convection would allow air to enter the lower end or side, pass over the heat sink and up and out the end that would be the top. I can see it running a few degrees cooler if on end but only if the lower end wasn’t resting directly on something which would partially block the vents if I recall correctly when looking at mine. So far no complaints of heat but then so far I’ve only run 1 tuner or when 2 tuners were active it was for just a few minutes while recordings overlapped a bit.
I run SageTV with Hauppauge 1750 OTA PVR. These are extremely sensitive to heat. My first 4 tuner Tablo (to move away from SageTV) came to the door as a hot brick. It was replaced with no issues. My point is though that I place both the Hauppauges and the Tablo on laptop cooling fans and I have no heat related issues with either device.
@tablotv, can the second usb port be used to power a small fan, such as laptop cooling fans suggested by @midnightjim?
can’t believe i didn’t even think about testing it out. but i want to get assurance about not disrupting power to the attached 2.5" drive, powered solely by the usb port.
I have used the 2nd port to charge my phone before, so it should work fine for a small fan.
Yep - 2nd port is there and available so feel free to use it how you see fit.
I have to add my two cents. My 4 tuner was running a bit hot and then I set it up on its side and last time I checked it was barely warm. It does seem to vent better setting on its side!
I have to add my two cents. My 4 tuner was running a bit hot and then I set it up on its side and last time I checked it was barely warm. It does seem to vent better setting on its side!
The heat sink is on the bottom, so if you position it as it is designed, there is a lot of heat build up between the heat sink and the surface it is sitting on. On it’s side, that heat sink surface is fully exposed to airflow and seems to remain a bit cooler.
Another option if sideways doesn’t work for you is to flip it over, so it is sitting on its top, with the bottom up. I find both work well, and better than leaving it sitting in its normal position. The hottest point on mine is the bottom left corner at the front of the unit - 110F - with the rest of the bottom at 95F - 100F - or just warm to the touch.
I ended up sitting mine on one of these and it has made a world of difference on stability of the Tablo.
I have a Tablo 4-tuner device and measure ~55C when all 4 tuners are fired up. Everything is working perfectly fine but the device is still very hot, in fact too hot to touch the base plate for more than a second.I'm wondering how you got approval from the appropriate US governmental agencies for something that could be considered a health hazard. I'm sure you guys did everything right but would you mind pointing us users to the regulatory approval document you got? This would be a more satisfactory answer than what I've seen from @TabloSupport so far.
If you think 55C is hot, you should feel the heat sinks off the back of some of my amplifiers. They are in the 65-70 range when pushing hard.
55C can cause 2nd degree burns if held for approx 20 seconds. Granted, why you would just grip your Tablo while it is recording 4 tuners, seems a little ridiculous and I would hope you would be smart enough to unplug it if it is that hot.
Insanely seems a bit of an exaggeration to me though…
If you think 55C is hot, you should feel the heat sinks off the back of some of my amplifiers. They are in the 65-70 range when pushing hard.
Thanks - but I think I’ll pass. I recall how hot some of the Alpine amps I had years ago in my Comanche used to run when I was doing contests and shaking the mirror off the windshield.
Our servers run so hot that you can’t run them with the cover off or any of the baffles out of place - they’ll cook.
It really doesn’t always take a ton of heat to cause instability in some high-frequency circuits. Or even not-so-high - I can recall when I was an auto tech and boss during summer months towed stalled cars off I80 near Altoona - the ignition module was NOT too hot to touch and yet a blast of freon was all it took to cool it enough to make it run again. So we’d replace the module. We had to keep 3 or 4 in stock all the time as they would break down in such a way that they’d become darned temperature sensitive.
Some things are just really picky about operating temperatures. I used to get my amps so hot I was afraid it would melt the carpet fibers, and yet I’ve seen PC circuits stop dead due to excess heat and you could still touch the chipset on the system board.
My belief is it’s not the actual temperature that’s causing concern, but rather it’s the relative temperature difference. So we’ve heated our house to reduce the difference between the tablo and everything around it.
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There definitely is some issue with the design of the 4-tuner Tablo. I’ve been experiencing pixelation issues on and off for weeks. It mostly happened when 3 or 4 tuners were busy during Primtetime. Now, it didn’t always happen so was hard to track down. The solution was easy, I now have a timer that turns on a notebook fan my 4-tuner device is sitting on. I let the fan run only during Primetime because it’s a bit noisy. All pixelation issues I experienced are gone and the temperature of the device is under control. This behavior is reproducible now that I know it’s temperature related.
And no, @TabloTV, this is NOT related to my attached hard drive which I know you always suspect when it comes to pixelation issue. I’m fine with this work-around but with all tuners busy the device (or at least mine) simply gets very hot which sometimes cause such issues.
We have kept our house at 67 all winter, down to 66 when my wife felt the need to cool off a bit.
Temp differences won’t be detected by electronic devices but operating temperatures will be.
The only time “differences” come into play is when devices cool down, heat up, cool down, heat up, etc. Heating and cooling cycles. This can cause component stress and in some cases where sockets are used, component “walk” where a part will literally rise up out of the socket in rare cases (very rare these days with so much surface mount stuff)
I used to work at an electronic engineering and manufacturing company, Compressor Controls Corp, I designed the control interface computers and set up the environmental tests - the devices would be heated up, then cooled down (we had a large nitrogen tank sitting outside of the manufacturing department test area). There was a chamber where the electronic control systems were placed and subjected to temperature extremes while running a battery of software tests I devised - intending to stress the hardware as much as possible while it also underwent the extreme temperature changes. (thrash a hard drive hard while heating and cooling it for example)
The devices won’t care what the ambient temperature is unless it’s so high that the device can’t cool off. There must be a temperature difference in order for cooling of the hot components to take place. The less difference there is, the less cooling that can take place. It’s sort of like the radiator in your car. If it’s super hot outside then the cooling system can’t remove enough heat and the engine runs hot. Same for electronics - I used to have an office with no AC and in the summer the room could reach 100 degrees - the computers would periodically lock up, but cool the room down a bit and the computers could release heat more efficiently and they didn’t lock up.
With passive cooling of electronic devices you WANT a temperature difference, the more the better to some extent. If the temperatures and humidities change a lot, wild swings, you can get things wet with condensation and cause major issues that way, like taking your digital camera outside on a hot humid day after it’s been sitting in a cool air conditioned house - it will get wet inside! But that should not be an issue with Tablo unless it is in your basement or in your attic in a climate like Iowa or MN would have.
Seriously, it’s the lack of ability of Tablo to rid itself of heat with the the totally passive cooling it has that is or COULD be a problem, not how much difference there is between Tablo and the ambient or room temp. Within reason, the more difference the better, and I mean the room being several degrees cooler.
With our house at 66 to 67 degrees I’ve had no Tablo heat-related issues. It might have helped that I also sat my Tablo quad up on an aluminum heat sink I salvaged from an old computer so it’s off the table, it’s got almost 2" of air circulation under it, and the fins of the heat sink help dissipate heat from the bottom of the Tablo since the air vents on Tablo are both low - that in itself is a cooling issue since heat RISES and as the air inside Tablo heats it’s trapped, can’t get out the top.
I spent 7 years studying environmental considerations of electronics as well as packaging and shipping since our controllers were shipped from Central Iowa to all over the globe including Eastern Europe, South America, Canada, Alaska, etc.