Recently I noticed an issue with users not connecting to a device ccr-1036-8G-2S+
The room temperature is: 26 c
I noticed a high temperature CPU
I opened the device and cleaned it, but to no avail, the same problem
It suddenly changes from 30 to 40 to 25 quickly

What is the problem ?

I bought a new device : CCR2116-12G-4S+
and put it in the same room. The results are excellent and the temperature is excellent and constant. Here are pictures of the new device

Generally speaking, there may be the need, besides the cleaning, to replace the thermal paste (or thermal pad) between the processor and heatsink.

But it could also be a case of the temperature sensor having issues, not on Mikrotik hardware, buit it happened to me in the past on standard PC motherboards, that the sensor went beserk reporting "crazy" temperatures, though 55-60 ° C don't seem like being so "crazy", it i more likely that it is just an issue of thermal paste aged and stiffened.

Anyway those temperatures are around or below the standard settings on 7.9 or later:
https://help.mikrotik.com/docs/display/ ... troloption

It may depend on the model and ROS version, but that on the new one you have the fans at 0 rpm and on the old one around 7500 or more, points to an issue with cooling (i.e. thermal paste/pads).

i have replace the thermal paste

Same result

I think there is a problem with the temperature sensor
Heat moves quickly 30. 40. 38. 25

I have seen reports of similar issues if/when some capacitors have gone bad:
viewtopic.php?t=162864
maybe you are in the same situation.

Yes it's the same problem, the capacitors are swollen

I will replace the capacitors and will update you on the results later

Thank you very much

I have a question, the capacitor located in ccr1036 It is 6.3v

Is there a problem if I replace it with 10v?

You can replace capacitors with higher voltage rating. You should very much stick to capacity rating (neither higher nor lower is OK) and voltage rating of replacement capacitor must not be lower.

Yes, 10 V is fine (actually better) if the old ones are 85° the tradition is that it would be better (if you can find them) to use 105° instead of 85°, but the real issue is finding good quality capacitors.

I changed the capacitors,
10v
680
105c

Attached is the product link. The seller is very good.
There is an excellent product and it ships to all countries of the world

https://www.aliexpress.com/item/1005006 ... 18027YUwQ8

============= The result. ===============
Now the performance of the device is stable, the temperature is constant, and the cooling fan has become less rotating

I had a similar problem with the CCR1036-12G-4S. The device was purchased in 2014 and all this time (that is, 10 years in a row) it worked around the clock. The first time we had to repair it was in 2017 due to a dead power supply (this is a known disease of theirs). Successfully replaced with Mean Well EPS-65-24. Recently the router suddenly went into boot loop. I decided that I would have to change the PSU again, but when I opened the case I saw these two swollen capacitors on the motherboard. Since they have a rather rare capacity rating, I had to solder a slightly larger 820uF instead. The router started up but began to work incorrectly. When ping devices in the bridge, return 22(invalid argument) errors. The devices did not ping it either, although they received the Internet from it. Restore from a binary backup it didn’t help either. Only by exporting settings to a text file and editing some parameters due to which it was not imported back after the reset I was able to restore full operation. Unfortunately, I was once again convinced that Mikrotik produces crude hardware and software, but what can you want for that kind of money.

I may well be off, but almost ten years of service with a power supply replacement and who knows how many after replacing the capacitors don't seem to me that bad.

Power supplies (not necessarily those from Mikrotik) tend to be a common enough failure point on a lot of electronic devices, unfortunately the trend is to use "proprietary" ones, often integrated in the main board or in satellite board with additional (besides the +/- main voltage lines) "strange" secondary voltages and control connections, so that replacing them is impossible if not with the appropriate spare (that the manufacturer rarely provides).

All this while we are invited to not waste precious resources, recycle, etc., BTW:

A heads up @moodnasser and others:
Besides the voltage, temperature, capacitance there is the tan(delta) also called Dissipation Factor, which is often not (never?) specified in the descriptions on Aliexpress. This factor shows is an indicator of the losses on the capacitance. This is especially important for power supplies as normal electrolytic condensers are not designed for low series resistance. The DF gets bigger as the series resistance of the capacitor gets bigger and the losses grow. That means the high currents which flow frequently through the capacitor in a PSU, will heat it up too much if you don´t buy special capacitors designed for power usage! Such capacitors are called low ESR (equivalent series resistance) and are not the same as low impedance capacitors.

You should only buy and replace electrolytic capacitors in PSUs by low ESR ones. Anything else might catch fire or if you are more lucky simply wear out too quickly.
Another benefit is that you don´t waste electricity on heating your capacitors.

There is a great Wikipedia article for further details: https://en.wikipedia.org/wiki/Dissipation_factor