386.10 on AC86U losing all 2.4Ghz devices (seemed to be fixed in 386.9.0)

[Gravityz]

with 51255 i only sometimes have this issue.
i upgraded to 51915 and instantly i got unstable wifi with disconnecting devices. i downgraded again to 51255 which is more stable.

i am beginning to suspect that other thing are involve
i disabled OFDMA to see if things improve

 

[heywire]

If you are experiencing issues with your 2.4Ghz network.

Step 1: Hard Reset the router (Hold the reset button on the back of the device for 5 seconds) and do not import a config.
Step 2: During the initial setup do not use capitals or special characters in the SSID or password fields for your 2.4 & 5Ghz networks, use only lowercase and numbers.
Step 3: Use whatever you would normally for your admin login and password.
Step 4: Connect devices on your 2.4Ghz/5Ghz networks.

Some part of the router has issues with capitals or special characters.

Step 3,5: Set 2.4 Channel Bandwidth to 2.4 MHz (Wireless/General/). Very important step to avoid instability.

Unless you live far away from any other 2.4 MHz networks, because then 2.4 MHz spectrum will be too crowded and the routers will wage war over it, resulting in disconnecting clients.
(can't guarantee that it'll work in that setting either as I've never tried it of heard confirmation that it does, but that's how the logic goes)

 

[L&LD]

I think @heywire means set 2.4GHz channel bandwidth to 20MHz (not 40MHz, not 20/40MHz).

 

[Deadmonty]

Maybe look at your wireless temperatures? I have a fan attached to the back of my AC86U which keeps everything very cool and have zero problems.

 

[doczenith1]

Maybe look at your wireless temperatures? I have a fan attached to the back of my AC86U which keeps everything very cool and have zero problems.

Same for me. After seeing this

May  9 18:27:01 kernel: thermal cooling_device1: turn off CPU#1
May  9 18:27:01 kernel: IRQ6 no longer affine to CPU1
May  9 18:27:01 kernel: IRQ28 no longer affine to CPU1
May  9 18:27:01 kernel: IRQ29 no longer affine to CPU1
May  9 18:27:01 kernel: IRQ30 no longer affine to CPU1
May  9 18:27:07 kernel: process 2565 (vpnserver1) no longer affine to cpu1
May  9 18:29:41 kernel: thermal cooling_device1: turn on CPU#1
May  9 18:29:41 kernel: CPU1: Booted secondary processor
May  9 18:39:01 kernel: thermal cooling_device1: turn off CPU#1

in the log I bought one of these https://www.amazon.com/gp/product/B00MWH4FL4/?tag=snbforums-20 and placed it behind my AC86U and have been fine ever since. CPU temps hover around 66 degrees C.

 

[Squall Leonhart]

high cpu temp would trigger a throttling event, if this causes the wifi to drop out then there is a timing flaw in the driver.

 

[Lotta Cox]

I had problems like that on 2.4 until I turned off Smart Connect.

 

[heywire]

I had problems like that on 2.4 until I turned off Smart Connect.

If you update the firmware you can probably turn it back on (like the new information in the parenthesis of this topic suggests).

 

[bibikalka]

Same for me. After seeing this

View attachment 53184

May  9 18:27:01 kernel: thermal cooling_device1: turn off CPU#1
May  9 18:27:01 kernel: IRQ6 no longer affine to CPU1
May  9 18:27:01 kernel: IRQ28 no longer affine to CPU1
May  9 18:27:01 kernel: IRQ29 no longer affine to CPU1
May  9 18:27:01 kernel: IRQ30 no longer affine to CPU1
May  9 18:27:07 kernel: process 2565 (vpnserver1) no longer affine to cpu1
May  9 18:29:41 kernel: thermal cooling_device1: turn on CPU#1
May  9 18:29:41 kernel: CPU1: Booted secondary processor
May  9 18:39:01 kernel: thermal cooling_device1: turn off CPU#1

in the log I bought one of these https://www.amazon.com/gp/product/B00MWH4FL4/?tag=snbforums-20 and placed it behind my AC86U and have been fine ever since. CPU temps hover around 66 degrees C.

This is one hot AC86u! What's the ambient temperature like where the router sits? Something is seriously off. Is something hot blowing at it? You may want to re-position it slightly to have cooler air go into the air intake. Things get fried faster 1 degree at a time, it's actually exponential with temperature. Every 5 degrees decrease the life of electric components by the same factor.


Mine at 28C ambient did this (hottest time in the room):

Sep 22 15:45:00 RT-AC86U-9988 Temp: 76.8 48.5 56.0 ; Mem free: 30888 KB; Swap used: 59608 KB
Sep 22 16:00:00 RT-AC86U-9988 Temp: 77.3 49.5 56.5 ; Mem free: 26952 KB; Swap used: 59600 KB
Sep 22 16:15:00 RT-AC86U-9988 Temp: 76.8 49.0 56.0 ; Mem free: 29168 KB; Swap used: 63280 KB
Sep 22 16:30:00 RT-AC86U-9988 Temp: 76.3 49.0 56.0 ; Mem free: 32848 KB; Swap used: 63496 KB

With just a single 80mm cpu attached on the side of the cpu (above LAN network ports) I get this now for the ~same ambient:

Sep 30 16:15:01 RT-AC86U-9988 Temp: 54.2 41.0 49.5 ; Mem free: 34584 KB; Swap used: 31572 KB; sda1 wrote: 1366.03 MB
Sep 30 16:30:00 RT-AC86U-9988 Temp: 54.2 41.0 49.5 ; Mem free: 32928 KB; Swap used: 31572 KB; sda1 wrote: 1377.75 MB
Sep 30 16:45:00 RT-AC86U-9988 Temp: 54.7 41.0 52.0 ; Mem free: 32304 KB; Swap used: 31572 KB; sda1 wrote: 1392.71 MB

P.S. Your radios are 5-8 C higher than mine without fan, but cpu is all 16C higher. Either very heavy load all the time, or the thermal pad dried out over time.

 

[Tech9]

This is one hot AC86u! What's the ambient temperature like where the router sits?

This router model had common thermal pads quality issue. When they start to deteriorate the CPU may reach 100C in normal operating range ambient temperature and the built-in thermal protection may start shutting down cores. Not necessarily user related (router placement) fault.

 

[bibikalka]

This router model had common thermal pads quality issue. When they start to deteriorate the CPU may reach 100C in normal operating range ambient temperature and the built-in thermal protection may start shutting down cores. Not necessarily user related (router placement) fault.

Right!

But in a way, CPU temp at reasonable ambient temperatures is a great indicator of the router "aging" stage, real age and level of usage. I think when cores start to shut down due to overheating with nothing unusual happening around it - the router is pretty much on the death watch.

The example above even had radio temperatures fairly high - I guess those thermal pads aged too.

 

[Tech9]

This router doesn't die from CPU overheating. The most common failure is burned step-down voltage regulator, specific one. It may happen on cold start and is unrelated to operating temperatures.

 

[bibikalka]

This router doesn't die from CPU overheating. The most common failure is burned step-down voltage regulator, specific one. It may happen on cold start and is unrelated to operating temperatures.

Right, but it's still due to the regulator's age. And CPU temp shows the rough working age of the router.

 

[Lotta Cox]

There was a firmware update for this router a few years ago that increased the temperatures dramatically. It was one after 384.19 b2
Was that ever fixed? Was in Asus code.

Current Temperatures: 46 °C - 53 °C - 56 °C on mine with fan and old FW

 

[bibikalka]

There was a firmware update for this router a few years ago that increased the temperatures dramatically. It was one after 384.19 b2
Was that ever fixed? Was in Asus code.

Current Temperatures: 46 °C - 53 °C - 56 °C on mine with fan and old FW

Yeah, that's what mine is with the fan on 386.12, pretty identical to yours other that my 2.4Ghz radio is cooler.
41.0 52.0 54.7

 

[doczenith1]

This is one hot AC86u! What's the ambient temperature like where the router sits?

As @Tech9 mentioned, the issue is assumed to be internal and related to cpu cooling. The router typically has little workload and is located on a desk in a well ventilated room that is climate controlled. The router ran at normal temps for over 4 years before exhibiting this behavior in early 2022 and is still in service today.

 

[bibikalka]

As @Tech9 mentioned, the issue is assumed to be internal and related to cpu cooling. The router typically has little workload and is located on a desk in a well ventilated room that is climate controlled. The router ran at normal temps for over 4 years before exhibiting this behavior in early 2022 and is still in service today.

So you have a ~2017 model to get 4 years in early 2022? The pads must have dried up and lost thermal conductance, both on the cpu and radio chips. An easy fix is an external fan, will probably get it to pre-2022 temperatures. I'd hesitate to try to fix it internally by pad replacement - probably it's at the end of its useful life.

 

[Lotta Cox]

Most of the heat problem is the firmware. There was an update that really increased temperatures. I am still on one of the pre hot firmwares. 384.19_beta2

 

[Tech9]

Most of the heat problem is the firmware.

The heat problem is in bad design and low quality materials used. The firmware you are talking about had CPU Idle disabled and was increasing the temperature with 4-5C, not 15-20C. This router with good thermal pads has CPU temperature under 80C in 25C room. The original thermal pads, pink in color, don't actually dry out, but leak silicone compound and make large oily stains on the heatsink. The firmware you are running is 3+ years old and had malware infecting it with unknown attack vector. I hope you have another firewall in front of this router. Otherwise - security risk.

 

[doczenith1]

So you have a ~2017 model to get 4 years in early 2022? The pads must have dried up and lost thermal conductance, both on the cpu and radio chips. An easy fix is an external fan, will probably get it to pre-2022 temperatures. I'd hesitate to try to fix it internally by pad replacement - probably it's at the end of its useful life.

I had to check my Amazon order history earlier to remember when I ordered the router which was November 30, 2017. As I mentioned in a previous post I do have a fan blowing on the back of the router since May 9, 2022 (again checking Amazon order history). At the moment I have no need to upgrade my router as this router is serving my needs quite well. I do have my old AC68U on the ready as a temporary backup solution should the 86U fail and I need to purchase a new router. Current router temperatures in my ~75 degree F (24 C) room are: 2.4 GHz: 48°C - 5 GHz: 54°C - CPU: 68°C