Bricked SXT2 with 6.39.2, now in boot loop and netinstall won't work

RouterOS General
1

Hello all.

I’d like to share you an experience I’ve had with updating a SXT2 (RBSXTG-2HnD) to current version 6.39.2.

After updating, the unit featured and endless boot loop. After climbing it down from the tower, I tried to reset it, do a config reset with a screwdriver and did manage to empty the device apparently. I get the Chirrrrrrrp -beep endlessly now.

Trying with direct cable with POE injector or through a hAP feeding power to it, few different cables and with few versions of Netinstall (5.26, 6.29 and 6.37) and with two different computers (both Win10 apparently), Netinstall procedure fails always to a symptom which I don’t understand. Monitoring the traffic with Wireshark I can see the unit hailing through BOOTP and requesting file VMLINUX to be fed via TFTP. Netinstall feeds it nicely (?) and the unit beeps once after that, but it never appears on the Netinstall device list and the unit is totally inaccessible after that nor it does not send any traffic anymore.

Analyzing more closely the Wireshark trace, I can see that every packet Netinstall has sent to the SXT, is acknowledged back with a ETHERNET FRAME CHECK SEQUENCE INCORRECT -statement which I do not know why that is happening and why the data sent is not accepted or has such errors.

The wireshark trace is available at https://pastebin.com/xVTG0Ucj

Current state of the SXT2 is that is is a paper weight, thus hoping to get it back alive somehow.

..
Erik

2

Try using a WinXP / 7 VM to rule out OS/driver issues, or an older laptop not running win10.

You can use VirtualBox is free. Tip: set VM networking to bridge mode.

For Win7 and up, you can download Microsoft ready-made VMs from https://developer.microsoft.com/en-us/microsoft-edge/tools/vms/

3

The OS issue did come into my mind also. I only have Linux VM’s installed now but need to look with an older windows. There might be a native Win7 machine also, lets hope for the best :slight_smile:

..
Erik