Hi,

I'm using around 30 of RB750UP for small BS(powering uplink and 1-3 omni or small sectors. UBNT Loco). I'm using OSPF+VPLS for tunneling clients so for CPU usage its no big deal for 750s.

In last month after temperatures go up, i saw sudden raise on CPU temp on 750UP. Its from 45-90C depending on how much sectors its powering and how much traffic it have. But CPU usage is almost the same everywhere and doesnt reach more than 10-15%.

What is the normal temperature for CPU, and is there some series that have temperature problems?

With this one I didnt had any problems, but with few with temp around 65C i had.

What power supply u use?

I'm wrong or Loco use 15V 0,8A power supply?

Hé Rextended everything all writhe
If the are nano M series use them 24 volt power supply's

Here is same RB few hours later.

What power supply u use?

Original Mikrotik 24V 2.5A...

Its Nano Loco M5 or Airgrid M5...

I think that the routerboard is overload with all the devices around.

Try with a independent POE for 1 or 2 devices to try out.

I think that the routerboard is overload with all the devices around.

Try with a independent POE for 1 or 2 devices to try out.

So what is a point to have a router with 4 poe out ports if You dont use them?

I want to know what is causing is.
I would disconnect certain devices.
So we can identify the problem.
Try please

power usage and temperature your router is running at does not fit. Power usage most probably is correct one. However, if the device is running at that temperature, you should feel that when hovering hand near the device.

Yesterday I upgraded one of them which has only 1 device powering and it was 45C and after upgrade to 6.15 and firmware 3.13 it got warmer.

I have couple 750UP hottest have 72 other around 55 but today is very hot day usually temperature is lower.
I thing on that with high temperature something is wrong with temperature sensor because from first day have higher temperature compare to other and on that is connected one 433AH and SXTlite.
On other with 411, Groove52, 2 x SXTlite temperature is 58 now but is very hot today APC ups on someplace have 45, 260GSP with 2 x Groove52, 2x433GL temperature 63 and APC UPS on some place have 50 but today is very hot usually I have lower temperature.
I thing you maybe have problem with temperature measurement like on my first device it is always hotter compare to all other 750 and 260gsp.

Over here 750Up is at 83. But strange thing happen few days ago and moments ago again. RocketM5 and NanostationM5 has been reset to default. At the same time! Any idea? Firmware is 3.13 and ros 6.18...

85°C seem to be a bit high. What is total power-draw from the device? What is an ambient temperature?

Also, you should know that RouterOS does not interact with external devices if not set to do by user.

In the same cabinet 1100ahx2 is measuring 31C and 750up is at 80C. Nanostation is drawing 5W and Rocket about 7W. Cpu is at 15%. Defective device or something else?

Can you post a picture how the routerboard is placed?

What about ventilation?
If these boxes are in a space where there is no ventilation and outside temperatures are going up, where does the CPU leaves its heat production?
Worse if is the box is in direct sunlight...

Imagine putting a nice thick blanket around the box and make it work a little. Temperature will probably run up until it crashes..

These '750' size boxes are very small. Meaning that all the electronics are compressed in a small space with hardly any natural ventilation, let alone force one.
The plastic box is also not helping a lot in radiating the heat out. Plastic is more an insulator than a heat transporter.

Maybe a simple small ventilator that moves the air around the boxes will help a lot.

I have a polyester cabinet where several boards (including one750UP are located). In the summer when the sun shines on it and the outside temp. was reaching 30 or higher I had a couple of times some radios failing because of the heat. (I literally 'burned' my fingers). So I bought a very simple, but sturdy, 220V ventilator for 15,-€ and that works now in the box for 3 years now. It just pumps the air around in the cabinet (with some vent holes) and since then never had any problems any more.

Bottom line; Units getting unusually hot are either not working good anymore or are not well cooled/ventilated.

In the same cabinet 1100ahx2 is measuring 31C and 750up is at 80C. Nanostation is drawing 5W and Rocket about 7W. Cpu is at 15%. Defective device or something else?

RB750UP can heat up only due to one reason - Power output on PoE-Out ports. Rest of the router generate heat next to nothing. Values you claim are nothing much if you are using 24V power supply provided with the router and cables are not very long (as there would not be huge voltage drop on those).

With 2 ports loaded, that anyway is a very high temperature.

I presume it is running latest RouterOS (or decently new release)

Dont get me wrong but something is wrong in 6.x OS (I know u have done tests in lab)-but I don't get it in 5.x temperature was somewhere around 45C max 50C
after upgrade
look at this picture two units (SXT,OmniTIk) power consumption at minimum
its night outside temperature is around 15-16C
in a day time RB750UP can reach about 84C -outside temperature max 25-26C max and when I touch RB750 its not so hot its more like around 45C
I have dozen of them and its not one or two showing high temperature but beside that RB750UP is running perfectly normal

if actual temperature is normal then we can check what we can do to make it to appear normal again. Can you send support output file to the support?