RB750 Reboot Loop

RouterOS General
1

Hello, I have an RB750 that seems ill.
This is what happened up to this point.
The day started out with the router in the store functioning fine. I logged into the router with winbox to update a script with the telnet function in winbox. The telnet window seemed frozen as soon as I opened it. It wouldn’t display the Mikrotik banner or drop to a prompt. So I closed the telnet window and opened it again. I got the same result. I closed it again and checked that I had functionality to other functions in winbox ex. traffic counters on the different interfaces. Things seemed fine there. At this point I did a system reboot and never heard from it again.
I got the router back to my office and started to bench test it. I connected a known working ethernet cable from my known working computer’s nic to the router. At first all five lights flashed on the top and that was it. I then powered it off and then back on again, all five lights flashed and this time I had a link light on the router, however I did not have link on my computer. I unplugged the ethernet cable from the router and the link light stayed on!
I powered it off again and then back on. This time I had link on both the router and the computer for about 10 seconds then the link went down. I’m assuming it rebooted again. Then I had link again for about 10 seconds then it rebooted again.
At this point I tried to reset it. (Just for clarification) I unplugged the power cable, found my trusty paperclip, held the paperclip in and plugged in the power and counted to 30. All five lights flashed while I was counting to 30 and since then they all flash every 11 seconds with no link at all.
My distributor tells me that I need to run NetInstall and request support here before they will process an RMA for me.

Thanks in advance!
Ron

2

Ron,

A couple of questions:

  1. What Ros version and what routerboot/firmware version were you running on that router?

  2. Have you recently upgraded the software on the router?

  3. was snmp disabled or enabled?

  4. can you netinstall it with 5.20 and check cpu-frequency settings afterwards?

3

ohara, Thanks for your reply!
Here’s the short answer to the problem. NetInstall worked on a different computer.


The computer I was using didn’t like NetInstall. I’m not sure if it had issues with the really old NIC or what.
I used my laptop to do a practice NetInstall on a working RB750 AND IT WORKED!
So i tempted fate and tried it on the 750 that was giving me issues and it worked too!

To recap what I have learned today. (Documentation)
This post helped http://forum.mikrotik.com/t/how-to-netinstall-rb750gl/57919/1
RB750 that has a straight through Ethernet cable connected to port 1 on the 750 and into a newer NIC on the computer
Latest version of NetInstall with the necessary mikrotik system files in the same directory as NetInstall
Set a static IP on the computer’s NIC like 192.168.88.50/24
Click Net Booting button in NetInstall, click the check box and type a static IP there as well 192.168.88.60/24, click ok
Unplug the 750 shove a pen into the reset hole in the back, and power it back up.
Hold the pen in for at least 25 seconds or untill the Act led stops flashing.
Wait a minute more and it should show up in NetInstall on your computer.