The heatpipe orientation does not matter. https://smallformfactor.net/forum/threads/tes … thermals.15858/
Heatsink is also hotter? If not and only the temps rising that means the heatsink is not mounted tight enough and there is a gap.

Thanks

They are as tight as the screw and spring combo allow. would also mean as the GPU and CPU are under the board, when horizontal it should overheat to as the gap would still be present, when vertical, it will shut down, Admittedly Onboard GPU not being used due to Nvidia card being used. may be warped pipe so see sawing on the GPU chip, nothing seem to move when i re applied the thermal paste.

upto 45 deg in horizontal light browsing, etc., 60 deg under gaming load, climes up to playing chicken in turbo (Windows hi performance Mode)

With heatpipes orientation does not matter. The liquid is transported using the capillary effect.
A thermosyphon relies on gravity to transport the liquid back to the heat source. The condenser has to be mounted above the heat source/evaporator for it to work.

Since your overheating problems occur when the condenser is above the evaporator it can't be related to wrong orientation of a thermosyphon as far as I understand. I would assume this mounting position restricts air flow/convection or directs hot air over another hot component so it overheats.

Pictures always help with further troubleshooting. 😉

Generic pic, i can do a better one when i get home..,

over heated with and without graphic card at the lower end of the case.

not tried vertical with fan and duct.

Thanks for the picture. I assume you are using the stand to mount it vertically?

would like to use it that way, but it over heats, so standing on it's side on four 18mm high rubber feet, would like to mount clipped to the table leg, out of the way

Yeah, I mean when you're putting it on its side you're using the stand to help convection/ventilation, right? So the lower air vents aren't blocked?

Yes you blocked the vents at bottom when it is in vertical orientation. There is no vents anywhere for front and back ports.

Raise the case above the table on spacers or little stick on feets so there is ventilation to flow into from bottom.

Cheers,

Doornkaat wrote on 2021-09-15, 10:19:

With heatpipes orientation does not matter. The liquid is transported using the capillary effect.
A thermosyphon relies on gravity to transport the liquid back to the heat source. The condenser has to be mounted above the heat source/evaporator for it to work.

I'd go with shouldn't matter because it should have been made with a stable absorbent liner that returns the liquid by capillary effect. And by stable, I mean something that didn't collapse, clog, turn to crumbs under heat stress or vibration. I have heard it told that cheaper heat pipes were just relying on gravity return, which makes them actually a thermosyphon, but probably sold as heatpipes to the unsuspecting.

It could also be that the heatpipe is working within design parameters, i.e. it was designed to shift about 60W worth, but had excess working fluid such that gravity return lets it work outside spec and cool 100W when upright, but the capillary flow isn't fast enough when it's in another orientation.

I tried it without the side casing, didn't help, that's why I suspected the heat pipe, Tdp on the CPU is 35w. Fans running, so I have air flow over the radiator, speeds up under load, but the radiator feels cool

library pic of rear of motherboard

Temp rise with air gap at bottom 1 Deg in 4 seconds, up to 77deg @25% 1397mhz CPU load, fan feel cool, the reverted back to horizontal back to constant 44-45 deg, gpu @ 33deg through out 0-5% load CPU constant through out.

when running at full pelt Gaming 90-100 % @ 2795Mz GPU @ 100% it depends on the external fan to stay below 67Deg and at 3Ghz+, just cooks in a few minuets

yes the radiators clear of dust etc.

BitWrangler wrote on 2021-09-15, 17:37:

I'd go with shouldn't matter because it should have been made with a stable absorbent liner that returns the liquid by capillary effect. And by stable, I mean something that didn't collapse, clog, turn to crumbs under heat stress or vibration. I have heard it told that cheaper heat pipes were just relying on gravity return, which makes them actually a thermosyphon, but probably sold as heatpipes to the unsuspecting.

It could also be that the heatpipe is working within design parameters, i.e. it was designed to shift about 60W worth, but had excess working fluid such that gravity return lets it work outside spec and cool 100W when upright, but the capillary flow isn't fast enough when it's in another orientation.

But OP describes the cooling to be worst when the device is upright so the heat source is underneath the condenser. Even if it is actually a thermosyphon it should work better in this orientation.

when it's layed flat, the CPU is on top, so probably cools more by convection though the grill, some heat being piped away,

other options
replacing with watercooling's out, due to no usable 12v power,

may be some big passive heatsink cut through the case may be an option, artic has a 47w cooler, or may be a graphic card cooler may be able to be grafted on. Nvidia bolt spacing at around 37mm which is the same as the spacing to the CPU heatsink pad. 150w TDP should be more than enough

The radiator should heat up as much as the cpu. if the cpu is a lot hotter than the radiator, chances are high the heat pipe is defective.
If you've got access to a flir camera you could visualize it.

What happens if you place a fan underneath when it stands upright? Of course leaving a bit of space underneath so the fan can pull in air, forcing convection.
I am really confused by why the device works better when sitting horizontally. It should be cooler this way if nothing is blocking the air flow.

That's why I reached out, would have thought convection would have been stronger, sorry no thermal camera, just touch, doesn't seem like much contact between the heat pad and the pipe. To expensive to replace, second hand could have same issue. Probably to much Hassel to "refill"

I like the power, and the low wattage of this unit. But would like to run at 4 core 3.2ghz

Heat rises...

Heat pipe when working right, should be warm all over over entire length of pipe, *any orientations*. If you feel cold to the touch at 77F when vertical, replace the heatsink.

Failed heat pipe is rare but I did find one at work where we repair all kinds of devices, (phones, notebook, consoles, etc), when co-worker was repairing the notebook. CPU was HOT, rest of pipe stone cold.
In all the years from when heat pipe came out, I didn't see one that did not work till now!

Cheers,

I heard that they do fail over time, but always thought they ment decades, little heat can be felt, Luke warm. May be conduction along the pipe.

I've seen people attach heat pipes to existing to improve cooling, what are they like for soldering with an electric soldering iron?

Have you tried looking up a replacement for the brand&model of your mini pc?
You didn't mention either and only shown us stock photos.

Though there can be a difference in construction,
some heatpipes have what looks like a porous layer on the inside of the pipe,
which when cracked, just adding a little bend in the heatpipe can cause a crack,
will cause the heatpipe to malfunction.