Router temperatures

[Tech9]

AC86U running Merlin 386.2 temperatures. Copper shimmed CPU, original thermal transfer pads on radio ICs, 12V 120mm fan running on 9V behind the router. The fan is not attached to the router as suggested in post #221 above, very quiet. RMerlin released the 386.2 and I fired up another AC86U to test it. This router has working radios, was LAN4 LED victim with one VRM only replaced. Update straight from original 41994 beta to 386.2 without resetting anything, 2+ hours uptime.

 

[webdriver]

I am a little late to report.
Upgrade my AC86u a week ago to 386.2 and notice the temp rise from 80 -> 85. Another 5 jump.
Scratching my head why it's happening again when we discussed about "CPU wait" magic. Now even with it still stay on that temp, nothing changes to ambient etc.

After a few days and I really worry whether the temp will keep going up when room temperature keeps up.
Find a usb powered fan from my son and place behind (distance about 20cm) router, wow, the temperature keeps drop down and now stay at 58. A total 85-58=27 drop with a small fan.

ASUS is really bad on this AC86U design regarding running temperature keep going up.


Update: the USB fan is a bit noisy as it's run on full speed. So I follow this article: https://www.instructables.com/How-To-Convert-A-Case-Fan-To-USB/
which I use a broken USB cable + a 140mm CPU cooler fan which I almost throw away. Since the cooler fan rated at 12VDC (full speed) so convert to use 5VDC still runs at low speed. Even I can barely feel "wind" blow out but when I put it against the router, it drops temperature from 85 -> 68 , not as much as that USB fan but enough to prevent a cooking Router.

 

[gattaca]

^^ Correct. We've talked about and proven this on several threads. We only have to push just a very small amount of air thru these units to lower the thermals dramatically. The slower the fan turns, the lower the noise but it still delivers very well! Stay safe, stay alive! Peace.

 

[DirtyFlash]

^^ Correct. We've talked about and proven this on several threads. We only have to push just a very small amount of air thru these units to lower the thermals dramatically. The slower the fan turns, the lower the noise but it still delivers very well! Stay safe, stay alive! Peace.

Just for the hell of it, I purchased one single 40mm x 40mm (approx 1 1/2 x 1 1/2 inches) USB fan and stuck it to the back of the router using some 2-sided tape on the 4 corners of the fan. Total cost, USD $1.50 off eBay. I was surprised how much of a difference one single small fan makes, not astronomical, but sufficient to drop the temperature into the mid-range of specifications.

 

[JWoo]

Asus by far has the best router firmware and with Merlin it is truly amazing firmware IMHO. But doggone nobody has worse thermal solutions than Asus. I have an old Netgear R7000 that with no modification runs at 62 - 65 degrees C in ambient temperatures of 20 - 26 degrees C. That's why that R7000 is still trucking along at 6 years of age. I am sure some folks on this forum might have an Asus router that has been around that long, but personally I have never had one last that long.

 

[vit5421]

I lift up back side of AX88u by 1 inch and CPU temperature dropped from 80C to 75C.

 

[Tech9]

I lift up back side of AX88u by 1 inch and CPU temperature dropped from 80C to 75C.

This helps a little too. I used to attach extra rubber feet to horizontal routers in the past.

 

[Darkje]

86u was running also very hot. I didn't care cause if all works it's fine with me. But my temp went higher. After I did the copper mod. Temp dropped to 60~65 degrees. No fans ...

 

[mromero]

This helps a little too. I used to attach extra rubber feet to horizontal routers in the past.

Router on wire rack so no need to raise its back. Blowing some air up its butt with a 12V CPU fan idling at 5V. Current ambient temp 32°C - Current Temperatures: 46 °C - 50 °C - 64 °C

 

[Kees17760]

I lift up back side of AX88u by 1 inch and CPU temperature dropped from 80C to 75C.

In the past i've used toothpaste caps as feet. It helps for all horizontal placed equipment. Even used it for my home stereo amp.

No need for heat, despite what others say about specs, safe margins etc.

 

[Sanna1967]

New stock firmware
ASUS RT-AC86U Firmware version 3.0.0.4.386.42643
1. Fixed CVE-2021-3450, CVE2021-3449 OpenSSL related vulnerability.
2. Fixed authentication bypass vulnerability. Special thank Chris Bellows, Darren Kemp – Atredis Partners contribution.
3. Fixed PPTP and OpenVPN server username/password GUI bug.
4. Fixed high CPU utilization issue.

 

[Kees17760]

New stock firmware
ASUS RT-AC86U Firmware version 3.0.0.4.386.42643
1. Fixed CVE-2021-3450, CVE2021-3449 OpenSSL related vulnerability.
2. Fixed authentication bypass vulnerability. Special thank Chris Bellows, Darren Kemp – Atredis Partners contribution.
3. Fixed PPTP and OpenVPN server username/password GUI bug.
4. Fixed high CPU utilization issue.

Well, well, well... Food for thought!

 

[Darkje]

High CPU utilization... I read... High loads on CPU??? Since my CPU is lurking...

Or did I miss read.

 

[Kendo]

Gonna try to use a silent cooler I guess...(AC68U)

 

[JWoo]

Gonna try to use a silent cooler I guess...(AC68U)

View attachment 33468

Why? 50 degrees for the radios and 70 degrees for the CPU is great, unless the router is in your freezer.

 

[Kendo]

Well, after I saw some much better temps with a little improvised cooling, it might worth a try. 70 C seems to be a little high for me.

 

[hiewliwen]

I have also a temperature problem with my AX58U.
Not the CPU temp, witch is correct but the 2.4GHz chipset.
It jumps randomly to 76°C and the the speed of the 2.4 network becomes very low.
It is always 76°C no matter what the room temperature is. Sometimes all is OK for more than 24 hours, and sometimes the problem occurs quasi hourly.
A small change in the WiFi parameters (BW from 20 to 20/40 for example) and the temperature returns to normal.
I have this problem with all 386 firmwares (beta,alpha or release). With 384.19 i never noticed this behaviour. Sometimes it returns to normal
without doing anything. As you can see I could capture this behaviour. Most of the time once it displays 76°C I must do something with the parameters to return to normal.
When it happens a few times a day, it is rather annoying.

View attachment 32003

I have the same exact issue and symptom. AX58U on Merlin 386.2_2. Mine happens daily and I had to schedule a reboot daily to get my 2.4Ghz back up.
Did you solve this?

 

[Darkje]

Guys if warrentee void. Just replace the cheap thermal pads for copper ones. It will perfectly fix the temperature without fans or anything.

Keep in mind to don't fix things that are not broken. The hardware is perfectly capable of handeling these temperatures. I modified my router. Just because I can. And if it fails I'll buy a new one. I simply don't care .

 

[clweb]

The problem on the AX58U is not the displayed temp of 76°. When the problem occurs, the 76° remain even if i try to cool if with a fan.
The problem is the 2.4 GHz does not work well in that case.
A reboot is not mandatory, a small change in WiFi parameters and the problem disappears instantly.
I also opened the case to replace the thermal pads with copper, but after 3 days I had this problem,witch is not existent on 384.19 firmware.

 

[JWoo]

The problem on the AX58U is not the displayed temp of 76°. When the problem occurs, the 76° remain even if i try to cool if with a fan.
The problem is the 2.4 GHz does not work well in that case.
A reboot is not mandatory, a small change in WiFi parameters and the problem disappears instantly.
I also opened the case to replace the thermal pads with copper, but after 3 days I had this problem,witch is not existent on 384.19 firmware.

I am probably the worst person to talk about the RT-AX58U. I sent my original new RT-AX58U back to Asus under their RMA process due to repeated crashes, and they sent me a refurbished unit. Within a week of getting it, the refurb was also crashing several times a day and I sent crash logs and my config info to Asus support at their request. Some days later, Asus support asked me to RMA the refurb unit as well, which I did. Asus declared the refurb unit also not repairable just like my original unit. When I spoke with support, they described the defect as "slow WIFI". My take is that there is a systemic hardware defect in the RT-AX58U.