Great video. Thanks! I received one of these from eBay and it was advertised as faulty due to 2.4GHz wifi not working. I suspect a hardware issue after performing all the necessary software checks. I have the proper equipment for removing SMD components but wonder if anything in the Amplifying section could be the issue since 5GHz works just fine?
If you trace along the traces on the PCB from the source chip to the antenna with a scope or spectrum analyser etc, you should be able to see where the signal stops and replace the part at that point.
Awesome tear down! I have the 3100 and am wondering how u popped the cover off...I can see in the video there are 3 tabs but I can’t see where to access them...do I run a credit card along the edges and pry it open? Let me know and great video man! 👍
+pacifikballa The lid on mine just came open easily once I took the screws out. Did you find the screws under the little rubber plugs that block the holes on the back of the unit?
Great that u have disassabled the 3100, but I do not like your shortcut of dropping to show how you lifted the cover off. I have taken those 2 screws out, but still my cover is "clued" in place. Have managed to lift it a couple om mm left nack corner, but from there I am afraid to use force. Is there more screws than those to in the back? Any other factors?
can you add the Thermal pads thickness in the discription off this video since it's getting older these tend to dry and be less conductive of heat. so people might wanna change these after a few years of heavy use. had this happen on my rt-ac68u and bought this Router as an upgrade/quickfix since it's CPU load was 100% when QoS'ing 2 different PC's playing network games and causing network lag above 5000MS wich never was an issue in it's previous years of service. suspecting the CPU to downclock itself to generate less heat i noticed that with the 2-screw heatsink design on the ac68u the board has bent ever so slightly causing contact to be lost in the center of the board and the heatsink. after i get it fixed again i plan to experiment with Merlin CFW on that one and maybe later on the newer AC88U if all goes well. i have the ac68u on hold at the moment since i i don't have all the Thermal pads in stock. rough sizes are 0.5mm under the outside heatsinks 1mm for the CPU and 2mm for the Radio-chips although i suspect the CPU is a 1.2-ish since i tried it with 1mm and not 100% sure it's not making good enough contact. Love your video as now you can see the board can't flex that much under heat with multiple screws on each Heatsink. i am however curious if someone ever used to extra Soldering joints to Hook up an extra 5 or 12Volt fan to that to keep it super cooled for parts in the world over 30degrees Celcius.
I'd have to tear it down again, but it is currently in use so it will be a bit difficult to take offline... Maybe someone else can measure their thermal pads and let us know.
That was really helpful. Subbed. You clearly know what you are talking about. Trying to figure out why an AC-RT-68U I bought for my parents is not broadcasting on 2.4 but says it is when it is actually only broadcasting on 5ghz and giving it a 2.4ghz SSID! Also, only one cpu core is showing in ASUSWRTmerlin lol. I gave them a new one as it was on it's last legs anyway. About a year ago the primary WAN failed (I think due to nearby lightning) and it has been working on failover ever since. It is so weird. The leds show 5ghz but not 2.4 ghz. I made sure to name them completely differently. It will only let things connect on 5ghz even though the SSID says 2.4. I checked with only 2.4 capable hardware and scanners. Digging deeper it gets even stranger. 'Temperatures' under 'Tools' show 5ghz as 'disconnected', Logs shows one cpu core fails to boot and only one cpu shows up in GUI. I tried to set up a 2.4ghz guest network to confirm it is not just a glitch. Both normal 2.4 and guest 2.4ghz will only transmit on 5ghz (even though they call themselves 2.4ghz) and the control channel is fixed on 0! I have tried lots of different firmware's, resetting, clearing nvram and asuswrt. Next step was going to be removing the heat sinks over the chips to see if anything burned out. Have you ever seen anything like this? Just interested and will probably tear apart if not. Anyway, thanks for the clues.
Sounds like the lightning strike killed something inside there in a weird way. I'd go for a new unit rather than chasing gremlins in the one you got... :)
This entire video is USELESS because the most important step is MISSING... Where are the screws that hold the cover in place and how do you get them out?
yea we know that the heat shields are not easy to remove. but you're a tech youtuber and this is a teardown video! we need you to remove them down. what do you mean by not pushing your luck? remove it well and attempt to put it back..
Actually right angled stubs are where you get radiation most of the time (such as vias or components on RF traces). And the right angles will cause massive reflection, causing standing waves and sometimes even damaging precision RF amplifiers.
Yeah it is actually. It's definitely modulating and demodulating Wi-Fi signals. It's not necessarily modulating signals to and from the ISP, but it is still a modem. Just not in the traditional sense, I guess.
@@polymetric2614 no it isn't. modulating and demodulating is usually from analog to digital and vice versa, which is not part of its functionality. A modem functionality would be included on a model that has a cable port on the back.
@@Steven-hq6df Any wireless technology is a digital signal encoded as analog. Wi-Fi happens to use the Direct-Sequence Spread Spectrum (DSSS) encoding technique. en.wikipedia.org/wiki/Direct-sequence_spread_spectrum The analog coax cable between your cable modem and ISP uses Quadrature Amplitude Modulation (QAM), also known as Quadrature Amplitude Shift Keying (QASK). en.wikipedia.org/wiki/Quadrature_amplitude_modulation They're both modulation techniques, for sending digital signals over an analog medium.
