RT-AC87U 5GHZ BAND R.I.P

[hggomes]

Suddently the 5GHZ led stop showing and no 5GHZ wireless transmission anymore, also the behaviour on WEBUI started (see the printscreens), this was all related with the 5GHZ band, inicially i thought something weird happened with the FW so i have done FACTORY DEFAULT RESTORE / CLEAR NVRAM, but i have not suceed.

After installing several FW versions, including ASUS stock, Merlin and DD-WRT, following the same steps the simptoms were exactly the same on all of them, no 5GHZ radio and WEBUI interface gets goofed when browsing 5GHZ band options.

The Quantenna OS does not boot for some reason, no way to login to the OS, and nothing related with Quantenna FW (qcsapi) works.

This seems a obvious Quantenna HW failure to me, i could see what was going on easily via serial console, but i will not since is still on warranty period.

On AC87U/R when the 5GHZ radio was disabled the temperature status was still there, the Quantenna system was never "offline", and now the status page shows it as DISABLED.

Anyone ever seen this exact scenario happening before on RT-AC87U model? I have read on this forum and others about the same problems happening on 5GHZ band, also stop working suddently and the users were forced to RMA even more than twice, but they never showed the details on this.

This seems quite a mess:

http://www.snbforums.com/threads/ac87rt-5g-not-working.18543/

http://www.snbforums.com/threads/ac87u-5ghz-not-working.21736/

http://www.snbforums.com/threads/brand-new-rt-ac87u-5ghz-radio-always-disabled.21085/

http://www.snbforums.com/threads/second-new-ac87-today-second-dead-5ghz-radio.19131/

RMA is the way...

 

[got_milk]

Were you not boosting the output signal strength past the limits set by Asus/Merlin firmwares with your own workarounds? The Quantenna chipset already runs fairly hot and close to the (now documented) limits of the chip - it doesn't surprise me at all that boosting past 100% drove the temperatures even higher causing the chip to fail.

 

[hggomes]

I wish that was the cause, at least i would have a motive for this to happen.

Unfortunatelly i dont use and never used the 5GHZ band, only for testing porpuses, if my 5GHZ radio was used more than a total of 10 hours was too much.

The 5GHZ radio was always OFF and temperatures when used were always the same 50-55º, so no overheating here, based on documentation TJMAX is 90º, it's too far away from it.

By default the 5GHZ band was set to 25dBm on my router instead of stock 15-23dBm (depending on the channel), for your information on AC87U model the .JP region for example uses 29dBm on some channels by default using the stock/original ASUS FW, so i guess based on your theory ASUS was frying all the japonese router owners and Quantenna chips if that was the case ah?

You should check what ive written and the links on the main post first, this is not an isolated case, it seems you only have read the part where the 5GHZ band died, no wonder why...

PS: You should forget my FW, you are starting to be addicted and paranoid.

 

[Deleted member 22229]

Were you not boosting the output signal strength past the limits set by Asus/Merlin firmwares with your own workarounds? The Quantenna chipset already runs fairly hot and close to the (now documented) limits of the chip - it doesn't surprise me at all that boosting past 100% drove the temperatures even higher causing the chip to fail.

I had the 87U for 5 days and the 5 ghz also failed for me. I agree not surprising after seeing the 5 ghz radio temp close to 70c it ran hotter then the CPU. Neddless to say it was returned for a full refund. I cant see any of these routers lasting very long unless you use some kind of cooling device under them. Not a very good design by Asus...

 

[hggomes]

Definitely it's not the best design i really agree on that, specially for the time it takes to boot/reboot the router, waiting for Quantenna OS environment to boot.

That was the main reason i replaced it with AC3200.

 

[TonyH]

Definitely it's not the best design i really agree on that, specially for the time it takes to boot/reboot the router, waiting for Quantenna OS environment to boot.

That was the main reason i replaced it with AC3200.

I had the 87U for 5 days and the 5 ghz also failed for me. I agree not surprising after seeing the 5 ghz radio temp close to 70c it ran hotter then the CPU. Neddless to say it was returned for a full refund. I cant see any of these routers lasting very long unless you use some kind of cooling device under them. Not a very good design by Asus...

Hi,
Poor heat sinking? I have a habit of opening up laptop or router when I get it to reapply HS compound. Not experienced premature failures.

 

[hggomes]

I never had temperature issues here, they where always fine.

You can see the printscreens on the first post, 5GHZ temperatures where between 50-55Cº.

I would say several routers dont have heatsinks/heatpads seated in place, i've tested several routers (AC68U) and theres huge differences of temperatures between them, that should not happen.

But theres always some differences on CPU VID, that has a significative impact on the temperatures also, but i think manufacters quality control fails TBH, they could simply add larger heatsinks or other soluctions to lower temperatures even more than usual they do.

A proof of that are the Netgear routers direct competitors having 10-15º lower temperatures.

Your procecure will for sure lower the router temperatures, but you will void warranty after.


This is something ASUS should do from beginning when the product was designed and tested, not the users, IMO this is a major flaw.

 

[TonyH]

I never had temperature issues here, they where always fine.

You can see the printscreens on the first post, 5GHZ temperatures where between 50-55Cº.

I would say several routers dont have heatsinks/heatpads seated in place, i've tested several routers (AC68U) and theres huge differences of temperatures between them, that should not happen.

But theres always some differences on CPU VID, that has a significative impact on the temperatures also, but i think manufacters quality control fails TBH, they could simply add larger heatsinks or other soluctions to lower temperatures even more than usual they do.

A proof of that are the Netgear routers direct competitors having 10-15º lower temperatures.

Your procecure will for sure lower the router temperatures, but you will void warranty after.

Hi,
Another possibility for radio chip temp. problem can be poor antenna connection or mismatched antenna.

 

[hggomes]

Hi, i don't think is the case.

Normally i also do exactly what you've done when i think the temperatures are higher than they should be, i open it and check the heatpads and heatsinks, my AC68U lower 20ºC after loose the screws from the heatsink, if you noticed the heatsink is bend when the screws are tight so it doesn't make any contact with the shielding, if you loose them you will see the heatsink completely plan and now making contact with the entire shielding, at the end this has a huge impact on the temperature results offcourse.

Take a look at those 4 pictures:

http://imgur.com/O0IWPJq,ferwjqm,mUaOLjj,uumc0Tx#0

This is obviously a major flaw from ASUS, is this their quality control? LOL

PS: This is just a small example, i also noticed on RT-N66U the heatpads were bad seated, almost lower temperature in 10ºC after.

 

[octopus]

Hggomes

It's good to know but Asus should take more responsibility, that's a hefty miss in production.
What were your temperature before modification? Normal what I could see, it is around ~ 76 - 80grd on the CPU for RT-AC68U.
What temperatur do you reach after modification? How do i open case ?

 

[hggomes]

Temperatures before were around 78-88º and after they went to 60-66º.

Opening the case requires to remove the sticker on the back and unscrew it after, your warranty will obvious be voided after that.

I added another heatsink inside on the back of the router so it could force even more the original heatsink against the shielding, making it even more flat and that worked perfectly. I also replaced the heatpads with bigger ones matching the size of the entire shielding, i uploaded all the pictures i took at that time, i will post it for you in a few.

 

[octopus]

Temperatures before were around 78-88º and after they went to 60-65º.
Opening the case requires to remove the sticker on the back and unscrew it after, your warranty will obvious void after that.

Okay, I dont care about the warranty. Just want to see if I can get down temperature.
But we're talking about the RT-AC68U here?

 

[hggomes]

Sure, RT-AC68U.

 

[hggomes]

Here they are:

http://imgur.com/8pZvSsz,CjqD6b5,v1...9s4Ix,g8aK9LR,mNyys5d,DkZVDio,KRg127O,sfGUdxq

 

[hggomes]

I just noticed that i uploaded also some pictures not related and repeated, just ignore them

 

[octopus]

Do you know where on the back screws are?
Will cut a hole for the screws, how many screws are under plate?
Can feel about the middle there's something underneath the sign, maybe you have a picture?

 

[hggomes]

Look at the 6th picture, theres only one screw under the sticker as i recall, remove it and then you need to force the case out with a credit card or similar tool.

 

[octopus]

Look at the 6th pictures, theres only one screw under the sticker as i recall, remove it and then you need to force the case out with a credit card or similar tool.

Okey then i know. Thank you.

 

[sfx2000]

The bendy heatsink, yeah, that's probably a concern...

 

[hggomes]

These two are even more noticable, no excuses for these kind of quality control failures.

In fact the heatsink being there or not its almost the same.

 

[sfx2000]

These two are even more noticable, no excuses for these kind of quality control failures.

In fact the heatsink being there or not its almost the same.

Yikes...