RT-AC86U random crash

[quadra2030]

RT-AC86U is crashing once a week without any apparent reason.. but when it runs, it's perfect - no WiFi dropouts, great speed and coverage (serving about 15 devices on Ethernet and WiFi).
I can't find anything interesting in crashlog, maybe some hw failure (is one from the beginning, September 2017)?
Basic config only - no mesh, AI protection, no USB devices/services active, running on 384.82072.
Any ideas?

 

[joe scian]

RT-AC86U is crashing once a week without any apparent reason.. but when it runs, it's perfect - no WiFi dropouts, great speed and coverage (serving about 15 devices on Ethernet and WiFi).
I can't find anything interesting in crashlog, maybe some hw failure (is one from the beginning, September 2017)?
Basic config only - no mesh, AI protection, no USB devices/services active, running on 384.82072.
Any ideas?

Yes - upgrade your firmware to latest

 

[vaboro]

May 5 07:05:11 crashlog: Kernel panic - not syncing: Fatal exception in interrupt

Have you tried resetting nvram?

 

[quadra2030]

Yes, nvram was cleared (factory default with initialize all settings checked)..

 

[vaboro]

Yes, nvram was cleared (factory default with initialize all settings checked)

How did you clear nvram?

 

[quadra2030]

Web GUI - Administration - Restore/save/etc. - Factory default with initialize all settings

 

[vaboro]

Ah, I see. You may try resetting nvram.
1) Power off your router with the power button.
2) Hold WPS button and push the power button while holding WPS button for at leaset 10 seconds. This resets nvram and starts CFE (you can check it if you connect to console).
3) Now you can release WPS button (the router can be in this state for as long as you wish; CFE is waiting for your commands on the console). And now power off the router with the power button again.
4) Disconnect the power cable (!) and push the power button again. This discharges the capacitors. If you're connected to console you may notice some LEDs blink as the capacitors discharge. Let the router rest for couple of seconds with the pressed power button, then make sure power button in not pressed (prepare for reconnecting the power cord).
5) Connect the power cable and start the router in a normal way.
This is the way I recovered from kernel panic causing a boot cycle on my router.

 

[vaboro]

I also noticed that TrendMicro's license may cause some weird things to happen. I would recommend withdrawing TrendMicro's license agreement before making a settings backup. After restore from backup TrendMicro's license can be accepted again.
I would also recommend not to restore from backup after nvram reset but to reconfigure the router manually. I think this is important because something in the backup may be causing the kernel panic.

 

[quadra2030]

Thanks for advice, will try manual reset and then set up router from scratch.

 

[vaboro]

Thanks for advice, will try manual reset and then set up router from scratch.

Are you on stock or merlin firmware? I suppose you're running stock. Am I right?

 

[quadra2030]

Yep, stock firmware.

 

[vaboro]

This method helped me recover from kernel panic on stock 384 and 386 as well as on merlin 384 and 386.