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Weirdly high temperature on new hEX PoE

Posted: Sat Feb 08, 2025 5:32 pm
by Miyuki
Hi, I have two hEX PoE - RB960PGS devices both sitting in a room with 10-15°C but the first (older one) shows a temperature of 37°C while the other (new one) shows 62°C
The new one with high temperature just sits there idle with no load. Should I worry about that? Because it seems like a huge difference and very high above ambient.
The weird thing is both are Model RB960PGS Revision r2 but one has a default CPU clock of 800 with a range of 720-1000 while the other has a default 720 with a range of 500-840
So it seems like they have a different processor inside, is that normal?

Re: Weirdly high temperature on new hEX PoE

Posted: Sat Feb 08, 2025 8:42 pm
by mkx
I'm not saying that definitely everything is fine. But with passively cooled devices it's kind of normal to see high temperatures of parts which generate heat. Are you sure that both are same model? Check /system/routerboard/print output ...

Re: Weirdly high temperature on new hEX PoE

Posted: Sat Feb 08, 2025 9:03 pm
by Miyuki
They are now on different voltages but the temperature was high even when the hot one ran from 24V supply
Cold one
[admin@Router] > system/health/print  
Columns: NAME, VALUE, TYPE
#  NAME         VALUE  TYPE
0  voltage      27.6   V   
1  temperature  39     C   
[admin@Router] >  /system/routerboard/print  
       routerboard: yes        
        board-name: hEX PoE    
             model: RB960PGS   
          revision: r2         
     serial-number: HGB09Y95TA1
     firmware-type: qca9550L   
  factory-firmware: 6.49.11    
  current-firmware: 7.17.2     
  upgrade-firmware: 7.17.2
[admin@Router] > system/routerboard/settings/set cpu-frequency=  
720MHz     800MHz     900MHz     1000MHz   
  [admin@Router] > system/routerboard/settings/print              
              auto-upgrade: no                        
               boot-device: nand-if-fail-then-ethernet
         preboot-etherboot: disabled                  
  preboot-etherboot-server: any                       
             cpu-frequency: 800MHz                    
             boot-protocol: bootp                     
       force-backup-booter: no                        
               silent-boot: no                        
      protected-routerboot: disabled                  
      reformat-hold-button: 20s                       
  reformat-hold-button-max: 10m    
Hot one
[admin@MikroTik_Switch] >  /system/health/print  
Columns: NAME, VALUE, TYPE
#  NAME         VALUE  TYPE
0  voltage      51.8   V   
1  temperature  63     C   
[admin@MikroTik_Switch] >  /system/routerboard/print  
       routerboard: yes        
        board-name: hEX PoE    
             model: RB960PGS   
          revision: r2         
     serial-number: HD1086861FK
     firmware-type: qca9550L   
  factory-firmware: 6.48.6     
  current-firmware: 7.17.2     
  upgrade-firmware: 7.17.2 
[admin@MikroTik_Switch] > system/routerboard/settings/set cpu-frequency= 
500MHz     600MHz     720MHz     840MHz    
  [admin@MikroTik_Switch] > system/routerboard/settings/print  
              auto-upgrade: no                        
               boot-device: nand-if-fail-then-ethernet
         preboot-etherboot: disabled                  
  preboot-etherboot-server: any                       
             cpu-frequency: 720MHz                    
             boot-protocol: bootp                     
       force-backup-booter: no                        
               silent-boot: no                        
      protected-routerboot: disabled                  
      reformat-hold-button: 20s                       
  reformat-hold-button-max: 10m        

Re: Weirdly high temperature on new hEX PoE

Posted: Sat Feb 08, 2025 9:08 pm
by mkx
They're both r2 ... and the cooler runs at higher frequency which is a bit counter intuitive.

So it may be about dried thermal paste/pads in hotter's cooling path.

Re: Weirdly high temperature on new hEX PoE

Posted: Sat Feb 08, 2025 9:30 pm
by Miyuki
What confuses me, is that they don't have the same frequency options it seems like they are not the same even when they should be

Re: Weirdly high temperature on new hEX PoE

Posted: Sun Feb 09, 2025 2:05 am
by jaclaz
It's not a couple of degrees, so first thing Is checking whether those readings are real.
There are reports of devices that have false temperature readings because of failed/defective components.
Ideally you should use a contactless thermometer, but as a first approximation you can feel them with your hand, one should be warm, the other definitely hotter.
39 seems to me "right" and 63 definitely "too high", particularly if the second has no or little load.
Another thing to check is - if you can - the amount of power each device draws (at a same voltage) when totally idle (no ethernet cables connected), there might be a sensible difference.
The difference in frequency is "strange" but unless the readings are way off it cannot be related.

Re: Weirdly high temperature on new hEX PoE

Posted: Sun Feb 09, 2025 2:11 am
by chechito
be aware voltage supply can influence temperatures