Teardown: Troubleshooting an ASUS RT-N66U Router
HTML-код
- Опубликовано: 22 дек 2018
- This is a teardown of an ASUS RT-N66U router. I had been experiencing degraded performance with it, and thought I would take it apart, and see if I could resolve the issues with it. This video includes verifying the operation of the power supply and inspection of the PCB and passive cooling components. The intent is to have two additional videos in this project, including:
Part 2 - Refreshing firmware from Rescue Mode, restoring configuration file and optimizing settings.
Part 3 - Additional detail into the components used in this product, and observations after making hardware modifications in Part 1.
Credit to this video for helping verify the better way to open the case:
• Video
Thanks for watching! 
Наука
Thanks for the video! By the way, you can check the temperatures of both of the WiFi transceivers even with the stock firmware. All you need to do is log in via telnet using your regular Web UI admin credentials and issue this command:
wl -i eth1 phy_tempsense
That’s for the 2.4 GHz band. And eth2 is the 5 GHz one. Just make sure that telnet is enabled in the Administration → System section before trying to connect.
Very good video series for this unit! Thanks for it!
Very similar disassembly (and heatsink pad) as the TM-AC1900/RT-AC68U. TYVM.
Thank you! Mine had a bad power switch, and you helped me get into it without destroying it!
I also now have a bad power spring switch.... how did you fix it ?
@@genroo I soldered a jumper wire across the switch's terminals. So the switch still moves, but it's effectively always on now. Not that it matters; none of my other routers have a power switch to begin with.
Wow, thanks! Subscribed immediately!
Hi, i have this Router but can't access it through utp cable, only by wifi, i updatet the (old merlin) firmware by the 2020 asus firmware.
The problem is that the nr1 Lan port led alway lids up with no cable in it and 2 + 3 don't lid up with cable in it, only 4 lids up when cable is connected, so it seems a hardware fault, any suggestions ? (exept ditching it).
I have an RT-AC86U AC2900 that stopped working these days. I have it for a little over 1 year. I have tried to do all the rescue processes but without success. The LEDs don't light up when I plug in the power cable. I have already tested with another new power supply but it is still the same. It stopped working a few minutes after doing a firmware update. It updated, worked normally for about 30 minutes and then simply went off. Is there any procedure that I can do to try to rescue my 86U?
Thanks for sharing 😎
My wireless went out and never came back on. Flashed back to asus FW then flashed to dd-wrt but no go. I wish I knew what the issue was?
What's inside each antenna? Could your issue be a broken wire?
I guess that microSD card slot is for a NAS?
I removed the plastic top of mine and it was still too hot for my liking so I made a 12v 60mm fan powered by a usb cable plugged into the back. (5v) Quiet and very effective, still working today (3-27-23)
What did you do to resolve? My RT-AC3100 5GHz band keeps randomly turning off (or totally non-functional most of the time), and when it does work, which is basically never, it refuses connections (authentication error) or speed is 6Mb/s max. Last week the router just completely stopped working (two LEDs were on, but no connections), until I performed a factory reset. I have used rescue mode to flash older firmware packages, but nothing has resolved these issues. Any insight regarding 5Ghz components that may be failing or have a loose connection? A lot of people have this problem, but I repair electronics everyday, so I'm hoping to find some information about relevant components. I have never worked on a router mainboard! Thanks for the video, hope to find out what worked for you!
Thats a bummer, but thanks for watching! I'm working on Part II of video right now! Coming out in a few weeks. Specifically with your situation - my guess is that it perhaps might be overheating. Does it seem to perform reasonably on the 2.4 GHz band or over ethernet? This might help further isolate the issue. Cheers!
I just got one of those for $10 Canadian used. I put openwrt on it and the wireless is garbage. I am trying to understand if it is just openwrt does not have the broadcomm drivers or something is wrong with it. The card slot can be used for media with openwrt, but I don't want to open it up. Also I am worried the antennas are not interchangeable, but some are 2 and 5. I am going to try moving them.
Can you comment on your before and after temperatures after replacing the thermal pads with paste?
I don't know. However, it seemed to spread the heat out better than the original pads, and kept the router more stable. Specifically it the 2.4 GHz radio (which seemed to always run hotter) didn't glitch out anywhere near as frequently. Thanks for watching.
@@TheCuriousEngineerChannel Actually, if you take a look at the board where the thermal pads were. Because of the difference in height, the board has permanently been warped to a concave shape. So with the thermal paste applied, the center would not be making much or at all any contact. I know because I've taken mine apart and applied thermal paste too lol. Except, I left the pads and just put thermal paste everywhere else. It would be hard to unwarp the board to make proper contact with the heatsink.
I am wondering if anyone can help me. The antena of my router came off and the cable connecting the antena to the router ripped. How can I fix it?
Thanks
You did not do any follow-up video did it help to introduce your temperature after adding some of these compared to the thermal pads
It certainly help stabilize the router, and I was able to use it for another 2+ years. I didn't do any specific testing on it to check temperatures, but it always "felt" cooler than before. I know, not highly scientific, but it's something. Thanks for watching!
Dude nice job what I did was connect a laptop fan cooler to the heat side so it dissipate and stays cooler
That for the win. Netgear nighthawk R7000 has now outseen 2 laptop coolers lol
Well, my Asus RT-N66R seems to be defective now. I still get the radio lights on (2.4 and 5.0 GHz), but devices (PC, smartphone, tablet) can only recognize wireless signal (2.4 and 5.0 GHz) when they are very very near to the router, like no more than 2 or 3 inches far. I've tried to replace the 3 antennas but it didn't get any better. In fact, the router seems not to be using the antennas at all. Any idea on how we can fix it? Thanks.
Oohhh, sorry to hear that. Just a guess but it seems like the PA (Power Amplifier) for the radio's has gone out or perhaps the power regulation to the PA's has failed. If memory serves, the PA is integrated into the 2.4 GHz and 5.0 GHz ICs. However, it might just be as simple as the main power supply flaking a bit, and it's providing just high enough voltage to power the logic stuff, but not the higher voltage needed for the PAs. Try a different suitably rated power adapter? Again, just a guess. Thanks for watching!
run it outside the plastic case... would be more cool looking that way and cool it much better.
Thanks for doing this video. I have an rt-n65u which has been going into a boot loop. I've tried all the methods for restoring but no luck. Thanks to you I have been able to get into the case but unfortunately mine doesn't pass the first test you do. The voltage on mine is 19.3v when off but when I turn on it drops to 0.6mv. If I turn off again the voltage goes up to just 17.6v and then rises slowly. Does this indicate a problem with the power supply?
You are most welcome! Do you have another known good power supply you can test it with? Is the unit turning on when it is showing 0.6 mV? If so, you might be probing different pins (like across the switch, for example).
@@TheCuriousEngineerChannel Thanks for the reply. I've managed to sort it now. It turned our to be the ethernet cable. I had already tested the cable, but I noticed that the router booted up and stayed on without the cable plugged in. After connecting another cable it now works again.
@@jonsumisu9016 is your other end device of that ethernet shorted?
@@mrizkic No, everything seems OK now I'm using another cable. Thanks.
Did u manage to fix the issues in the end? I had to open my up because of the power button.
I did, and I am still using it! The crazy cooling solution seemed to help! ASUS issued a few firmware updates recently that helped, as well. However, I have two other videos to finish on that project - I got sidetracked! Look out of those in the near future!
@kidsnd274, have u managed to settled the power button?
@@calvinliew6846 Yup, took out the spring and just taped the button in. Works like a charm
@@Kidsnd274 I think my 1 is not the power button problem, maybe the input socket problem probably, because I see the adapter is lighting in blue, but when plug in to the router input socket and nothing happen to the router.
what was you fix? my power button is also damaged, i remove the spring, know it works
Hey. Thanks for video, helped me to open it! :) Well, on mine router only three leds for LAN are solid lid all the time - nothing else (not even the Power led). Power supply is ok - tested with another one. Any ideas to fix it or is dead?! :( Thanks
You are welcome and thanks for watching! Can you get it into recovery mode?
@@TheCuriousEngineerChannel I was trying with WPS holdng 5 sec... If you meant that?! I would appreciate it if you can give we a hint(s) how to get in any kind of recovery modes! Thanks
STAY AWHILE AND LISTEN!
Got goosebumps once I heard the guitar lol
Do you know if soldering the antenna header connectors will allow 9 antennas using merlin or custom firmware?
Unfortunately I'm thinking not. The 2.4 GHz and 5 GHz wireless controllers are designed for a Dual-Band 3x3 MIMO array. While the BNC connector pads are there, and are routed in the PCB; they do not appear to be connected to anything using this particular Broadcom 2.4 GHz and 5 GHz controller. Cheers!
Hi my N66U suddenly stop working, now 3 blue lights turns on quickly for a sec when i power on, then it kinda have a dim flashing here and there for that 3 lights, and then no more lights afterward, any idea where I should check? I checked the switch, getting 19.57V when it's off and around 19.49V after it turns on
Perhaps continue measuring the voltage for a while after the lights start acting up. If the measured voltage starts sagging, perhaps you might to replace the power adapter? Also, perhaps check that one electrolytic capacitor in front of the DC power port on the board, and see if it is bulging or leaking. Good luck!
@@TheCuriousEngineerChannel I actually came here for a similar issue. Three lights turn on bright for a moment, then the power and all the lights turn on, then the power starts flashing, then all of them turn off and just the three over "2" "1" and the internet flash dimly. If I turn the device on, then connect the power adapter to the wall it does not power on and the adapter LED light flashes dimly. If I turn the device off or just connect the power cord after it's in the wall, I get the 3 lights flashing. I'm measuring 18.86v and that drops to 18.64v but a few times it went to 12v when I turn it on. I have a second power supply from a n56u and it does the same thing. My home made bench supply is broken but I could measure current draw once I fix that.
Another thing to note is that FR9886 in the top left is a 2A step down converter on the underside of the board. This component gets too hot to touch and led me to do some testing... Vout is connected to GND and there is a second FR9886 with the same exact issue...
Many of the capacitors in the center are touching GND on both sides so I really wonder how much time this thing is worth. Someone was throwing this router away along with a gig hub that has similar issues when powered on so I wonder if this was a power surge.
Thoughts?
@@Gkid8 Hey! Thanks for watching! If a known good supply is dropping down to 12 Vdc when powering up, it seems to me that the switched-mode power supply (SMPS) in the supply is folding back. This is a normal thing for it to if the output current draw is exceeded. It's not uncommon for components to get too hot to touch inside a device, which is usually at around 60C / 140F for more people, so perhaps check it with a temperature sensor or IR thermometer? If it is above 90C / 194 F, then I think you found your issue! That converter could have shorted out internally, or one of the supporting components could have failed short. It could be a simple fix, but without knowing more or seeing it, I can't say for sure. Hope that helps!
@@TheCuriousEngineerChannel Yeah, I checked and the ethernet hub connected to it had the exact same issue and centered around one of the main chips. I think there was a voltage spike and it fried something in both devices. I threw them away
same issue with mine, i kind of wanna repair it coz it is a good & stable router...but just don't know where to start with the repair...
my router rt12+B1 is becoming very hot .what i do can you tell me?
Bummer. Not much to go on. Does it still function? Does anything smell like it is burning or melting?
The toggle on my power button broke on this Any idea how to get it to just stay on or how to replace it?
Mine broke too. I simply use a small plastic piece and super-glued over the switch to depress the toggle switch permanently.
Remove the lid as shown in the video. Take out the printplate. Remove the very small retainer for a spring on the power button. Remove the small spring itself. It should now click into "power on" for ever. That's it. No glue needed. If you want to power down the router, just remove the power adapter.
@@HermanCaron perfect, thanks, it helped me!
@@HermanCaron Thank you. This worked for me as well!
hi my RT-N66 cant turn on, the adapter blue light is on, I suspect the Ac input socket defected, any clue to check? Many Thanks bro
Hi! If you haven't checked out the latest video I've posted, I'd start there. Otherwise, if you have, perhaps check out to see if the switch is actually working - which I walk through in this video, through checking the voltage. You'll need a voltmeter of some sort. If the power LED is coming on the adapter, that likely indicates there is *some* voltage at the output, as that LED is on the low-voltage, DC -side. Maybe I'll do a quick video on that :). Hope that helps. The solution @Kidand274 performed might work as well!
@@TheCuriousEngineerChannel today I jz check with multimeter from the input Vdc which I suppose to get 19V, but I got 0.15V before I switch on, and when I push the button it shows -0.15V where i suppose to get -19V.
My RT went out and it turned out to be the on off switch, I removed a retaining clip and the spring in back of the on, off "push" in switch and now it just stays on.
@@Dillinger86 i did the same, remove the spring and everthing works
Thanks, now my smart TV dongle has a nice meaty heatsink and backplate lmao they really don't want you to poke around in there.
on related note back of my board has actual signs of manual touch up soldering. Had this router from new for god knows how long.
My 5ghz is going out (the 5ghz lights go out), is this router salvageable?
Tha same problem in router Asus AC5300 , first the 5Ghz band , now 2.4ghz , help
@@lostcontroltibia fuckin rip
thanks you video help me to remove the spring from the power button. the power button goes eyerytime in off position (couldn't hold the on position) know the 9 years old router works again, hopefully for 5 years more.
When almost eight years old, the power switch failed mechanically on mine, too (even though it had been operated only rarely and not for a long time). At the time of failure, the router was undisturbed, except that the weather was hot). The switch seems to be a changeover type, but I assume that the connection made when the switch is "out" is of no importance, so I shorted the "normally open" contacts by soldering on a piece of wire. This restored operation. The switch is of little value, anyway, since power can be removed by taking out the power plug or by unplugging the external supply. The basic problem seems to be that the switch is of poor quality.
I had the exact same problem. Wanted to take out the entire switch but taking out the spring is much easier. Thanks or helping me fix it!
Have same issue. I was not certain which pins I could safely soldier together so I used a toothpick to place friction on the button to keep it in. I thank Curious Engineer for posting how to open the case.
what is that you did dude, ok you took it apart, what part did you fix????????
Thanks for watching! I fixed nothing and everything. :p Seriously, I was recording general troubleshooting that I usually do, and found a few things that surprised me. I did state those things in the first video, but will clarify as part of the next one that is coming up very soon.
Where’s part 2 and 3?
They are coming soon. There wasn't much initial interest in that video, so I moved on to other projects. Then well, honestly, I then forgot about it. I did fix the RT-N66U, and am still using it. I have the second video shot and am currently editing! Look for it soon!
@@TheCuriousEngineerChannel It's 10 Months later now, I'm curious what happened to the other videos? :D
@@DasKroenerTier Hi! Have you watched "Rescue That Router! The Lost Tutorial -- How to Rescue and Securely Recover the ASUS RT-NT66U!"? I put it as a card at the end of this video.
@@TheCuriousEngineerChannel Dang, I didn't saw it :D thank you :D
Very interesting but when you powered it up with no antennae ,I was like Noooooooooo!
Haha! Why?
Asus products quality is so high!
Look for a heatsink in a TP-Link Archer C7 lol