Cool my Merlin'd RT-AC68U down?

[SFBear]

The router is running ok, but seems a bit hot to me.

It's a former T-Mobile router (from Amazon, no worries), with its software reverted to an RT-AC68U then to the Merlin build for that model. As such, its CPU runs at 800 Mhz already.

The CPU is up to 75 degrees C, and wireless radios are up to 52 degrees C.

These temps seem a bit high, so I'm wondering if under-volting is possible, to reduce heat production.

If so, can someone please show me a step-by-step to accomplish it?

 

[martinr]

Leave it alone. It’s quite normal. There are several threads about it on this forum if you want to read the history. Try a search with
“$9 cooling fan” for starters. https://www.snbforums.com/threads/9-router-cooling-rt-ac68u-example.26733/

I experimented - for fun - with my first RT-AC68U. Reseating the heat sinks with proper heat-transfer paste, brought down the cpu temp by 5degC if I remember correctly; then adding fans brought it down something like another 10degC. (Details in that thread.) When I got another RT-AC68U for a spare, I never even bothered improving the heat transfer to the heat sinks, let alone adding fans.

There’s no problem; it’s normal, and there’s no solid evidence (but some armchair theorising) that it does any harm whatsoever to the router or reduces its lifespan in the slightest way.

Use your time more profitably getting to know Merlin’s firmware and some of the possible extras (eg AB-Solution, Skynet, AMTM) that some of his brilliant, leading disciples have developed.

Oh, and welcome to the forum.

 

[Lazarus56]

Well, here's what I did for my RT-AC1900P (the BestBuy version of the AC68U):
I ordered one of these - AC Infinity MULTIFAN S3, Quiet 120mm USB Fan for Receiver DVR Playstation Xbox Computer Cabinet Cooling

from Amazon for $12.99 - I plugged the USB-A connector into an unused USB port on the back of the router, stood the fan on its rubber feet, and directed the airflow onto the back of the router. Here are my temps as I write this:
Temperatures 2.4 GHz: 39°C - 5 GHz: 42°C - CPU: 51°C

It ain't fancy, but it works for me...
Laz

 

[SFBear]

Thanks for the replies so far.

- External fan.
- Temps are normal, don't worry.
- Optionally redo heatsink paste to lower temps slightly.

 

[AndreiV]

Those temperatures are not high. The AC87U is the router you could make toast on.

I sat mine on a small notebook cooler from CoolMaster , having returned 4 faulty AC87U's , I have an AC3200 which sits on the cooler and runs @ 2.4 GHz: 39°C - 5 GHz: 44°C - CPU: 50°C

 

[elbubi]

having returned 4 faulty AC87U's

You had 4 dead AC87u? Do you think temps were the culprit?
I own a 87U also, and I had to put a cooling stand beneath it cause CPU would reach 90º C here in summer (5G VERY hot also). Now with the cooler it gets as hot as 60ºC "only". (Pics here)
Hope it last for long!

Cheers.

 

[AndreiV]

You had 4 dead AC87u? Do you think temps were the culprit?
I own a 87U also, and I had to put a cooling stand beneath it cause CPU would reach 90º C here in summer (5G VERY hot also). Now with the cooler it gets as hot as 60ºC "only". (Pics here)
Hope it last for long!

Cheers.

Temperatures didn't help but the main issue is the Quantenna WiFi system. There were so many router failures retailers were refunding on 2 year old units.

With the Ac87U you either get a dud or router that works perfectly .

I had 4 x 87U's , one after the other , the retailer decided to stop the RMA cycle and I got a refund and upgrade to the AC3200.

 

[elbubi]

Thanks for your Answer Andrei.

Could you please elaborate a bit about your Quantenna issues? I've hadn't tested it thoroughly yet (can't connect my most used devices due to FFC locking channels 144-161), but I would like to see if its working alright or be able to reproduce your issues.

Kindest regards!

 

[AndreiV]

There are endless posts/threads about the many issues on this forum.

The biggest problem was 5Ghz Wireless dying .

 

[elbubi]

Ok, we'll look into it, hope mine won't die. Thanks!

 

[SaveMyRouter]

Connected to a PC case fan with external USB.

Legend: 2.4 GHz - 5 GHz - CPU
Current Temperatures: 41 °C - 43 °C - 61 °C​

Without the fan, they were like:

51 °C - 53 °C - 87 °C​

 

[elbubi]

@SaveMyRouter

I do also had dramatic temps decrease using a notebook cooling pad.

I noticed that, even though my 2.4 and cpu are the same as yours, my 5G sits MUCH more wormer , at this very moment they look like this:

Wonder why your cooling is that much more effective on the 5Ghz side.

Regards!

EDIT: Sorry, misread thread title, you own a 68U while mines 87U. Now it makes sense. Cheers!