I am having a strange problem with an R450G: from time to time all lights turn off, User Led (green one above the Blue for Power On) lights up, no messages on log but “router was rebooted without proper shutdown”. Most of the times it reboots normally just after unplugging/replugging power cord, but sometimes User Led turns on again before the first beep.
As I found the case something hotter than usual on top, I took it off and did some tests: with nothing connected but a notebook with WinBox, System Health showed 39 to 44oC. Blowing hot air temperature increased to 51oC and… it happened!
But, if instead of blowing hot hair I increase processing to 100%, temperature goes to 58oC and stabilizes.
So my questions are:
does this test assure the “freezing” is caused by overheating? Or is there something else I am not taking into account?
once I’ve readen in other forums devices working with 60 - 70oC, is there any hardcoded upper-temperature limit I can change?
RB450 series is pretty old by now and has a history of bursting capacitors. Bad caps lead to bad power delivery which leads to system instability and crashes. There are threads on this forum which go into detail about diagnosing caps condition and resoldering new caps on the board. RB450 case is trivial to open so start by doing that and checking the board for bulging or burst caps and possible loose heatsinks on chips.
Capacitors look OK, the router was bought less than one year ago and is working in an Air Conditioned room. This, and some tests where it did not freeze at 57oC or froze at 49oC is making me think there is another problem…
Is there a way to know how old is the hardware? I mean, when it was fabricated?
It does not tell you the condition of the caps, only that it is some 3 years old.
51 deg is not a critical temperature at which it would crash.
Bad caps is the most likely reason. Maybe you are just unlucky.
Caps are not leaked nor bulged… even so, can they be bad?
I did three other tests now:
updated RouterOS to 6.47… same problem
did a factory reset… same problem
changed power source to 12V… same problem! But at 57oC once and 52oC after. Strangely, in all tests with this power source the router managed to reboot automatically
In no test at all the autosupout file was saved: does that mean this is not a memory corruption or a bad configuration or the like? I mean, will a “software/firmware” problem always generate a autosupout file, but not a hardware problem?
Actually Mikrotik always reboots some time after freezing: green light (User Led - the one above the Blue for Power On) turns off and it does a normal reboot, saying in log “router was rebooted without proper shutdown”. Temperature shows 50oC, so it seems it reboots when temperature decreases.
This makes me think there is a process running continuously monitoring temperature (and maybe other parameters) and shutting down the system and rebooting it again.
50oC is not that high - there are threads in this forum with very high temperatures reported.
Does anybody know if this limit can be changed somehow?
Couldn’t be the other way around? A process starts using 100% CPU. The system freezes and reboots. Since there is less load, the temps go down. Maybe the problem isn’t the temperature: maybe it is a symptom.
That is what I thought when started to make tests, but processing is very low, 1 or 2%. And, if ambient temperature is low, the router can sustain 100% processing for a long time before freezing.
But it seems something is being triggered by the temperature, or together…
It is sounding more and more as though some physical component (perhaps caps, still without externally-visible degradation?) is defective on your board. If it isn’t the caps, then it’s probably not worth troubleshooting and servicing, unless you are already really adept at dealing with surface-mount components…
You already said you tried a different power supply. As a last-ditch, have you tried underclocking the CPU?
Yes, I did! It stands more time processing before reaching 50oC, but once reached… it freezes the same way…
Workload is not going to be high for this router, but ambient temperature certainly will, so, sooner or later it is going to freeze - probably midday, with everybody connected…
I am using it for less than one year, users started to complain two months ago… in winter! If it was brand new it deteriorated very fast, if it was not… why it didn’t freeze in summer?!
That makes me think of some protective upper temperature limit put in place recently…
Will downgrade and see what happens!
But… for what reason do you reboot yours every 8 hours?
Did a last try: downgraded to the version you are using, 6.39.1… same problem.
Don’t know why I am still not conviced this is a hardware issue… but I’am not expending more time on this.
So, to summarize for future reference:
RB450G “freezes” at about 50oC, reboots automatically some time later
sometimes it goes beyond 50oC
Factory Software 6.29.1 (2015) and Factory Firmware 3.24
in use for less than one year (don’t know if was used before) in an Air Conditioned room
started to freeze two or three months ago (winter)
capacitors look OK
tested with factory default configuration
tested 6.39.1, 6.41.4, 6.42.6 and 6.42.7
tested 12V power source
tested reducing clock to 300MHz
supout file is never created, there is nothing in logs
Concluded that there is a hardware problem preventing the unit to operate properly above 50oC (until someone discover a high temperature limit somewhere )
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There is a very simple way to prove it to yourself beyond a doubt:
Buy another 450G. Put it in the exact same environment (in the exact same physical space, even…have it take the place of the old one) running the exact same config.
When the new one ends up working fine under those conditions, you have your answer.
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