Router keeps crashing and rebooting continuously

[Klonoa]

Hello,

My AC86u router has been randomly restarting recently, with consistently high CPU usage. It only has the amtm's LED SWITCH CONTROL installed and an OPENVPN service running. I have noticed many kernel errors in the logs.The log is provided below.

**Info:**

- System: 386.13.2 Merlin
- Add-ons: amtm; LED SWITCH CONTROL

 

[jksmurf]

Hello,

My AC86u router has been randomly restarting recently, with consistently high CPU usage. It only has the amtm's LED SWITCH CONTROL installed and an OPENVPN service running. I have noticed many kernel errors in the logs.The log is provided below.

**Info:**

- System: 386.13.2 Merlin
- Add-ons: amtm; LED SWITCH CONTROL

I can't comment on the logs (not experienced enough) but there's quite a few reported instances of that router model (a) Overheating and (b) this (and indeed other ASUS models) having PSU (Power Supply) Failures and (c) a 'blown' VR Chip, which someone managed to fix theirs on, by replacing the VR chip, but it takes very specialist work (see video), as it's around a 3mm x 3mm 16pin surface-mounted chip that needs desoldering and a new one soldered on.

Crashes appear common. See here too; and here; and here.

If you're lucky, it's (b) and it's a simple fix and you don't have to poke around in the settings (unless it came about due to a recent settings change and is repeatable). Just use (borrow) a PSU with the same Volts / Amps Rating and Polarity and try it; if it is stable, then swap out the PSU.

If not, then look at the settings. If not then, maybe it is the Router failing (hope not, for your sake, unless you need an excuse to convince your significant other it's time to upgrade, then you're on to a winner ...).

 

[ColinTaylor]

There's quite a few reported instances of that router model (a) Overheating and (b) that and other models having PSU (Power Supply) Failures and (c) a Blown VR Chip, which someone managed to fix theirs on, by replacing the VR chip, but it takes very specialist work (see video), as it's around a 3mm x 3mm 16pin surface-mounted chip that needs desoldering and a new one soldered on.

Crashes appear common. See here too.

If you're lucky, it's (b) and it's a simple fix and you don't have to poke around in the settings (unless it came about due to a recent settings change and is repeatable). Just use (borrow) a PSU with the same Volts / Amps Rating and Polarity and try it; if it is stable, then swap out the PSU.

If not, then look at the settings. If not then, maybe it is the Router failing (hope not, for your sake, unless you need an excuse to convince your significant other it's time to upgrade, then you're on a winner ...).

You reported the same symptoms when you were only running Skynet.

I suggest you remove any USB drive that you may have plugged into the router. Then perform a factory reset using the GUI option Administration - Restore/Save/Upload Setting > Factory default > Restore (with Initialize all the settings checked).

Then setup you router again manually (without importing an old saved config file). Do not enable remote web access, AiCloud or AiDisk.

 

[Klonoa]

I can't comment on the logs (not experienced enough) but there's quite a few reported instances of that router model (a) Overheating and (b) this (and indeed other ASUS models) having PSU (Power Supply) Failures and (c) a 'blown' VR Chip, which someone managed to fix theirs on, by replacing the VR chip, but it takes very specialist work (see video), as it's around a 3mm x 3mm 16pin surface-mounted chip that needs desoldering and a new one soldered on.

Crashes appear common. See here too; and here; and here.

If you're lucky, it's (b) and it's a simple fix and you don't have to poke around in the settings (unless it came about due to a recent settings change and is repeatable). Just use (borrow) a PSU with the same Volts / Amps Rating and Polarity and try it; if it is stable, then swap out the PSU.

If not, then look at the settings. If not then, maybe it is the Router failing (hope not, for your sake, unless you need an excuse to convince your significant other it's time to upgrade, then you're on to a winner ...).

I understand! However, I am currently unable to determine the exact cause. Previously, my AC86U router's temperature ranged between 158-194°F without a fan, but after adding a fan, it stabilized around 138-144°F. The memory usage at idle is about 70%-80%. If I enable Samba, the available RAM drops to around 90MB.

Can these observations indicate whether it is a hardware issue? If not, are there other methods to diagnose the problem that don't involve physically modifying the router?

Thanks!

 

[jksmurf]

Can these observations indicate whether it is a hardware issue? If not, are there other methods to diagnose the problem that don't involve physically modifying the router?

I don't believe these Routers have monitorable warning systems like the OBD Scanners on Cars that identify specific HW failure . It would be nice... but very unlikely to happen. RAM usage is not an indicator AFAIK. I cannot comment on Temperature as an indicator, but have a look at the linked threads for similarities or dfifferences to your Temps.

To test it, I can only echo what @ColinTaylor suggested. Return the unit to absolute stock by resetttng it, set it up with minimal options (and no USB etc) and test it for a while.

If it claps out at this point, it is very likely a HW issue of some kind (VR Chip, PSU...).

If it works OK, then add items back one by one, testing it for a while (days?) each time.

Sorry I cannot suggest any more than that at this point.

 

[Klonoa]

You reported the same symptoms when you were only running Skynet.

I suggest you remove any USB drive that you may have plugged into the router. Then perform a factory reset using the GUI option Administration - Restore/Save/Upload Setting > Factory default > Restore (with Initialize all the settings checked).

Then setup you router again manually (without importing an old saved config file). Do not enable remote web access, AiCloud or AiDisk.

Yes, but I later removed Skynet and kept only amtm and LED SWITCH CONTROL. All the features you mentioned earlier are disabled. I have retained AiProtection and the SAMBA service on USB. I haven’t tried a factory reset yet.

I don’t fully understand the contents of the logs. Could you help analyze them?

Thanks!

 

[Klonoa]

I don't believe these Routers have monitorable warning systems like the OBD Scanners on Cars that identify specific HW failure . It would be nice... but very unlikely to happen. RAM usage is not an indicator AFAIK. I cannot comment on Temperature as an indicator, but have a look at the linked threads for similarities or dfifferences to your Temps.

To test it, I can only echo what @ColinTaylor suggested. Return the unit to absolute stock by resetttng it, set it up with minimal options (and no USB etc) and test it for a while.

If it claps out at this point, it is very likely a HW issue of some kind (VR Chip, PSU...).

If it works OK, then add items back one by one, testing it for a while (days?) each time.

Sorry I cannot suggest any more than that at this point.

Thanks, buddy! I'll check as advised. It's what I can do for now.

 

[jksmurf]

I don’t fully understand the contents of the logs. Could you help analyze them?

As above, log interpretation is not an area I know anything about. When I check mine (which is rare), I just look for errors and pseudo errors and try to google them.

1. These reported kernel errors (and there are many of this type in your logs)

Jul 18 07:59:00 kernel: *** ERROR: [send_redir_page:614] # redir_url=http://10.19.97.2:80/blocking.asp?app_cid=3&app_id=5&mac=882D5322EAB9

appear related to AiProtection or Parental Control as noted by RMerlin. See also here.
It makes sense to do what Colin says above to rule these out.

2. Your 'openvpn tainted' log reports also appear here by others, but I have no solution.

3. Your 'aswebsrv tainted' errors do not google to anything at all; seems rare.

Note that there is a 386.14 beta 2 for that model (updating your stable FW), but I am not sure if the changelog signifies improvements for your case.


Asuswrt-Merlin Changelog
========================

386.14 (xx-xxx-xxxx)
- NOTE: Reminder that all models on the 386.xx series will
stop being supported by Asuswrt-Merlin at the end
of 2024.

- UPDATED: Merged with GPL 386_52805.
- UPDATED: wget to 1.24.5.
- FIXED: WPS wouldn't start on RT-AC68U (note: starting through
webui was fixed, however starting through button is
still broken for the RT-AC66U_B1, including with
stock firmware).

 

[Klonoa]

As above, log interpretation is not an area I know anything about. When I check mine (which is rare), I just look for errors and pseudo errors and try to google them.

1. These reported kernel errors (and there are many of this type in your logs)



appear related to AiProtection or Parental Control as noted by RMerlin. See also here.
It makes sense to do what Colin says above to rule these out.

2. Your 'openvpn tainted' log reports also appear here by others, but I have no solution.

3. Your 'aswebsrv tainted' errors do not google to anything at all; seems rare.

Note that there is a 386.14 beta 2 for that model (updating your stable FW), but I am not sure if the changelog signifies improvements for your case.


Asuswrt-Merlin Changelog
========================

386.14 (xx-xxx-xxxx)
- NOTE: Reminder that all models on the 386.xx series will
stop being supported by Asuswrt-Merlin at the end
of 2024.

- UPDATED: Merged with GPL 386_52805.
- UPDATED: wget to 1.24.5.
- FIXED: WPS wouldn't start on RT-AC68U (note: starting through
webui was fixed, however starting through button is
still broken for the RT-AC66U_B1, including with
stock firmware).

My AiProtection and Parental Control are in a semi-enabled state. The former only has the non-malicious website blocking option enabled, and the latter has a scheduled offline mode.

The results I found for the second and third issues are similar to what you mentioned—most suggest ignoring the error or provide no solutions.

If the situation doesn't improve after resetting, perhaps I'll consider using the Beta version.

Regardless of the outcome, I truly appreciate your assistance!