rb750 management hangs

Hardware MikroTik hardware general
1

Hello,
my rb750s have problems with periodic hangs.

this is how it behaves:

Reply from 10.10.0.223: bytes=32 time=25ms TTL=62
Reply from 10.10.0.223: bytes=32 time=156ms TTL=62
Reply from 10.10.0.223: bytes=32 time=229ms TTL=62
Request timed out.
Request timed out.
Request timed out.
Request timed out.
Request timed out.
Request timed out.
Request timed out.
Request timed out.
Request timed out.
Request timed out.
Request timed out.
Request timed out.
Request timed out.
Reply from 10.10.0.223: bytes=32 time=78ms TTL=62
Reply from 10.10.0.223: bytes=32 time=27ms TTL=62

Ping on these devices periodically hangs for cca 1minute. this occurs on routeros 4.10 and 4.11
4.5 is fine.

devices are not routing thus i dont know if it hangs completely.
switching works fine, but configuration is a little complicated. do anyone else have this problem?


ps. same thing happened to me when i configured rb250gs, but thats a different forum.

2

did u try with another PSU?

3

i have 3 devices behaving like this. and a few more with older ros working fine.

4

Did you check if the rb750 rebooted during the non-responding pings? Check the System/Resources Uptime.

I have a rb750 for testing here and it is giving me just trouble.
The router is currently doing nothing other than reporting the status every 10 min to a server.
The RB 750 is connected to a 3KVA UPS unit like all the other equipment.

  • I tried 3 different power supplies with different voltages (9-18)
  • The router reboots with no apparent reason
  • The router hangs with one or two LEDs on (e.g. port 1 and 2) no matter if the network cable is plugged in
  • The router is not responding (ping, winbox), but the LEDs are still responding when I unplug the network cable

I checked for capacitors, but they look fine to me.

I have a RB450G running the same test job and the last reboot was two weeks ago and the unit is running without any problems.
My RB750: S/N starting with 25BA01A3…/025

Since other people are running many of the rb750 with apparently no problems, maybe I got a bad one.
But the low price does not make sense to send it back to the supplier as the freight charges, customs etc. will be more than a new router. But I cannot tell our customers to buy this unit if it is giving these kind of problems.