RB1100AHx2 CPU 50C, fan not working

Hardware MikroTik hardware general
1 
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  MikroTik RouterOS 5.12 (c) 1999-2012       http://www.mikrotik.com/

[admin@xxx] > /system routerboard print 
       routerboard: yes
             model: 1100AHx2
     serial-number: xxx
  current-firmware: 2.39
  upgrade-firmware: 2.39
[admin@xxx] > /system routerboard settings print 
            baud-rate: 115200
           boot-delay: 2s
       enter-setup-on: any-key
          boot-device: nand-if-fail-then-ethernet
        cpu-frequency: 1066MHz
     memory-data-rate: 533DDR
        boot-protocol: bootp
  enable-jumper-reset: yes
  force-backup-booter: no
          silent-boot: no
[admin@xxx] > /sys he print 
           fan-mode: auto
            use-fan: main
          active-fan: none  <-------------
            voltage: 12V
            current: 820mA
          fan-speed: 0RPM   <-------------
        temperature: 32C
    cpu-temperature: 50C    <-------------
  power-consumption: 9.8W

Is 50C okay for this CPU with no fan working? CPU load is approx. 20%. Uptime is 5 days.

2

50C is very low. No problems there.

3

Thank you very much Normis, in contrast please explain this (another router, very similar load):

[admin@yyy] > /system routerboard print 
       routerboard: yes
             model: 1100AHx2
     serial-number: yyy
  current-firmware: 2.39
  upgrade-firmware: 2.39
[admin@yyy] > /system routerboard settings print 
            baud-rate: 115200
           boot-delay: 2s
       enter-setup-on: any-key
          boot-device: nand-if-fail-then-ethernet
        cpu-frequency: 1066MHz
     memory-data-rate: 533DDR
        boot-protocol: bootp
  enable-jumper-reset: yes
  force-backup-booter: no
          silent-boot: no
[admin@yyy] > /system health print 
           fan-mode: auto
            use-fan: main
         active-fan: main
            voltage: 12V
            current: 904mA
          fan-speed: 4373RPM   <------------
        temperature: 31C
    cpu-temperature: 38C       <------------
  power-consumption: 10.8W
[admin@yyy] > /system resource print 
             uptime: 5d1h42m36s
            version: 5.12
        free-memory: 1501940KiB
       total-memory: 1555212KiB
                cpu: e500v2
          cpu-count: 2
      cpu-frequency: 1066MHz
           cpu-load: 18%
     free-hdd-space: 24404KiB
    total-hdd-space: 41768KiB
  architecture-name: powerpc
         board-name: RB1100AHx2
           platform: MikroTik
4

I don’t understand the question.

Fan off = temperature 50C
Fan on = temperature 38C

This is normal!

5

There are 2 routers. Very similar load (20-30% CPU). One of them never activates fan, and the other never turns it off :slight_smile:
That’s the problem. I don’t understand why? :slight_smile:

I also have another problem: the third router. It’s not connected to the network, it’s idle on my desk now, and his fan is constantly at 10000-11000 RPMs! Why? Why 3 different routers works in different way?

[admin@MikroTik] > /system health print
           fan-mode: auto
            use-fan: main
         active-fan: main
            voltage: 12V
            current: 744mA
          fan-speed: 10526RPM   <-------------
        temperature: 34C
    cpu-temperature: 32C
  power-consumption: 8.9W
[admin@MikroTik] > /system resource print
             uptime: 1h2m50s
            version: 5.12
        free-memory: 1525256KiB
       total-memory: 1555212KiB
                cpu: e500v2
          cpu-count: 2
      cpu-frequency: 1066MHz
           cpu-load: 0%
     free-hdd-space: 24932KiB
    total-hdd-space: 41768KiB
  architecture-name: powerpc
         board-name: RB1100AHx2
           platform: MikroTik

Edit: yeah, I can hear that 10krpm fan. It’s very very loud.

RB1100AHx2 FANS
6

The one that has 38 degrees C and ~6K rpm is ok,

The one that has not turned fans on at 50 degrees C →
open box and try to plug fan on other headers, also, try to rotate pins 180 degrees and plug them back on, if you have some other 3 pin 12V fan, you can try to attach it there, see if it works.

Third one that runs fans at full tilt - measure middle pin of the fan header (with fan attached) voltage to the ground, at low temperatures there should be lower voltage, if there are 12V please write to support for further details.

7

Thanks.

This one is unfortunately in production :slight_smile: I’ll have to schedule a downtime, I’ll follow your ideas.

At 31C CPU on main fan there’s 11.2V, on aux fan there’s 12.1V.

8

contact reseller for RMA application.

9

Thanks, done.

I did that a moment ago, rotated pins, tried to attach main fan to aux header and vice versa, attaching another fan and nothing worked. I also measured the voltage on the middle pin, and it was, obviously, 0V on both headers.

It seems system tries to do something with 37C sys/51C cpu, because /system health print interval=1s shows that active-fan is changing every few seconds from ‘main’ to ‘auxilliary’ to ‘none’, but nothing works (fan-speed is 0 and no fan is rotating).

[admin@yyy] > /system health print interval=1s
           fan-mode: auto
            use-fan: main
         active-fan: auxiliary  <-------
            voltage: 12V
            current: 715mA
          fan-speed: 0RPM   <-------
        temperature: 37C
    cpu-temperature: 51C
  power-consumption: 8.5W
10

it seems that second board that has 0V on middle pin also has to be RMAed. Contact your reseller.

There always has to be some voltage reading between middle pin ground if header is active.

That alternation is as designed - if RouterOS detects that on one header nothing happens it tries to turn other one up, this is why you see the alternations. If you want you can change from auto to manual and then only header you set to be on will be on.

EDIT: Could you also send S/N of these boards to support@mikrotik.com

11

Yeah it’s the same in RB1000 and it always worked excellent.

Done.

Thank you for your help. See you in Warsaw possibly :wink: And expect few more things in the meantime.

12

My RB1100AHx2 is at 57C cpu temperature, and none of the fans are working.
Same as chojrak11 said, the router tries to use fan main, then auxiliary, then none.
What should I do?

13

with connected fan do the following measurements as described previously. See what are results.