What should I do if the Mercury Tenda router 5G WiFi cannot be found? 2.4G is still connected, but 5G is missing. I followed these five steps to save it.

The Mercury D191G at home annoyed me last week. The phone is connected to 2.4G and everything is normal, and the TV box is still there, but the WiFi with the "-5G" suffix has disappeared from the list. My first reaction was that the router was broken, so I turned off the power and restarted it. However, after waiting for two minutes, 5G still didn’t appear. It was later discovered that the problem was not with the machine at all, but with a switch and a channel in the background causing trouble.

This kind of thing happened to my friend's Tenda AC10, but the backends of the two companies were called different, so I almost gave the wrong route. Today I will talk about Mercury and Tengda together to save you having to follow other people’s tutorials and flip through the menu for a long time.

First, separate "can't be found" and "can't be used"

5G WiFi is missing, don’t rush to click “Network Failure” to fix it. Let’s look at two facts first: Is 2.4G still there? Is it that the mobile phone simply can’t find any WiFi?

If 2.4G is still normal, it means that the router has not crashed, and the power, broadband, and wireless master switches are basically alive. The problem is likely to be on the 5G line alone. If even 2.4G is gone, it’s another direction. You have to check whether you can enter the background first. Refer to 192.168.0.1 Can't open, can't get in In that article, first solve the login entrance.

I first typed a command on my Windows laptop to see the current situation.:

netsh wlan show interfaces

There is a line of "frequency band" in the output, which shows 2.4GHz and channel 1. This shows that the machine has been connected to 2.4G, and the 5G SSID has not been scanned out at all. This difference is very important. But I can’t use it even though I’m connected. It’s a problem with DNS, gateway, and dial-up. ； I can't find it. It's a matter of radio frequency and broadcasting. Don't mix the two in practice, as doing so will only make it more confusing.

Mercury's background will first turn off multi-band integration, and then the 5G name will appear separately.

My D191G originally turned on dual-band integration for "automatic signal switching". 2.4G and 5G share the same WiFi name. Later, when I changed the settings once, I could not find a single 5G name. Mercury's switch, the old interface is not called "dual-frequency-in-one", but "multi-frequency-in-one". It took me a long time to find it for the first time.

The approximate path of Mercury’s old interface is as follows: Browser 192.168.0.1 or melogin.cn , click "Wireless Settings" → "Basic Settings" and look down to see if there is "Multi-frequency integration". If so, turn it off, and then 2.4G and 5G will be divided into two names. You can then set a separate name for 5G. For example, mine is called "shunot-5G". The new firmware has just changed it to "dual-band-in-one", and the location is also near the wireless setting.

If you can't find the 5G name, it actually shows "enabled" in the background, or it may be that wireless broadcasting has been turned off separately. Some versions of Mercury call it "wireless broadcast" or "SSID broadcast", make sure this item is turned off. There should be one more name in the phone list immediately after dual-band separation. Wait for about 30 seconds. Don't rush to refresh just after saving.

I want to understand the logic behind the integration and separation of Mercury’s dual frequencies. How to separate 2.4G and 5G on Mercury routers I dismantled it once, when it was for network distribution for the sweeper. The phenomenon was not exactly the same as this time, but the switch was the same.

Tenda's backend is called Dual-band Optimization, don't look for it through Mercury's menu.

My friend's Tenda AC10 is even worse. I told him based on Mercury's experience, "Look for multi-band integration in the wireless settings", but he rummaged through the menu and said there was none. Later I let him in tendawifi.com , find "More Functions" → "Advanced Settings" → "Wireless Settings", the switch inside is called "Dual Band Optimization". The old firmware is not called dual-band-in-one, nor is it called multi-band-in-one.

It’s very clear when you compare the names of the two families.:

After he turned off dual-band optimization, the phone list returned to two WiFi names. There is another detail here: After Tenda changes and saves, the router will usually automatically restart the wireless. The phone may be disconnected for a few seconds and then reconnect. Don't think it's broken again. Tenda separates the specific pitfalls of dual-band, How to separate 2.4G and 5G on Tenda router I also made a point here that the menu positions of the old and new firmware are different.

Don't use automatic 5G channel, I ended up getting stuck on the DFS channel.

After my Mercury turned off the multi-band integration, an extra "shunot-5G" did appear on the phone, but it disappeared again when I turned around. This is more concealed than the switch: The 5G channel automatically switches to the DFS channel.

The default channel of the router is usually "Auto", and it will pick one that it thinks is clean. In 5G channels, 36, 40, 44, 48, 149, 153, 157, 161, and 165 are relatively common. ； The 52, 56, 60, and 64 in the middle belong to DFS channels and are theoretically made to make way for radar. Once there is a radar signal near the home, the router will automatically avoid it. Some old mobile phones, old network cards, and National Bank equipment do not support DFS well, so 5G appears in and out of the list, or even disappears directly.

My solution was to go into Mercury wireless settings and change the 5G channel from "auto" to fixed 149. After saving and restarting wireless, the 5G name stabilized and never disappeared again. If your router only provides 36-48, you can also fix 36 first and see if the device can recognize it later. When changing, try to return the bandwidth from 80MHz to 40MHz. Some old network cards have poor compatibility with bandwidths above 80MHz, but it is not necessary to change them all. First solve the channel.

If you want to verify which channel your phone has scanned, you can type on your Windows computer:

netsh wlan show networks mode=bssid

It will list the BSSID, channel and frequency band behind the same WiFi name. Seeing that the channel falls between 52 and 64, you can basically face the pitfall of DFS. This is not the same thing as whether the signal is strong or not. How to adjust the transmission gear if the 5G signal is weak? Where to set the signal strength of Mercury Tenda router I wrote before that the problem today is not the wall stalls, but the fact that the names simply don’t come out.

I also conveniently measured the variable bandwidth. I have a 2017 Lenovo Xiaoxin Air at home. The wireless network card’s support for 80MHz is sometimes good or bad. 5G is sometimes on the list and sometimes missing. After I returned the Mercury 5G bandwidth from 80MHz to 40MHz, it became stable. The cost was that the negotiated rate dropped from 866Mbps to around 400Mbps. The broadband at home is only 300M, so I can’t feel the difference at all. The bigger the bandwidth, the better. If old equipment can’t keep up, routers have to make do with it.

Older mobile phones only support 2.4G. Don’t blame the router for being too far away from the wall.

There is another situation where no matter how you modify the router, it still doesn’t work.: The device itself does not support 5G. I took a 2016 Redmi Note4 and the current Xiaomi 10 at home and scanned them at the same time. The Xiaomi 10 could see 5G, but the Redmi Note4 only showed 2.4G from beginning to end. After checking the parameters, I found out that the old Redmi only supports 802.11n, and it is single-band 2.4G. It doesn’t recognize 5G at all.

So don’t be in a hurry to reset your router. First, take a mobile phone that is sure to support 5G and scan it while standing next to the router. If it can be seen, the old device is inherently incapable of 5G and has nothing to do with the settings. To determine whether the device supports it, look at "802.11ac/ax" or "Dual-band WiFi" in the specifications table on your mobile phone. On your computer, click on the wireless network card properties in the device manager, and you can also see the supported frequency bands.

The attenuation of 5G through walls is more obvious than that of 2.4G. My D191G is placed in the TV cabinet in the living room. The bedroom is separated by two walls. There are two or three 2.4G slots left, and 5G often cannot be scanned out. This is not a bad thing. It is more practical to move the router out of the cabinet and put it in an open position, or to add a node at the door of the bedroom, rather than working in the background. Don't mistake "physically out of reach" as "function is broken" and restart it repeatedly.

This time I condensed the sequence into six steps, and I will follow the same steps next time

Looking back, Mercury 5G disappears in these few layers, from simple to troublesome.:

1. First make sure that 2.4G is still there and that the entire router is not down.
2. Take a mobile phone that supports 5G and stand next to the router to scan again.
3. Go to the background and turn off multi-band integration/dual-band optimization, so that the 5G name appears alone.
4. Check the 5G wireless broadcast switch, don’t be hidden alone.
5. Change the 5G channel from automatic to 149 or 36 to bypass the DFS channel.
6. Move out cabinets, reduce partitions, and finally consider factory reset or firmware upgrade.

My most valuable experience this time is: If 5G cannot be found, turn on the background first, don’t turn on the router power supply first. I spent almost an hour fiddling with the step of changing the channel from automatic to fixed, and it only took me two minutes to actually solve it. The menu names of Mercury and Tenda differ by a few words, but the underlying logic is the same, "first divide the frequency, then check the switch, and finally nail the channel."

One final reminder: I put factory reset and firmware upgrade at the end. Because once Mercury and Tenda are reset, the broadband account, WiFi name, port mapping, and static binding are all gone. Instead, it is easy to change from "5G cannot be found" to "the whole family is disconnected." If you get to that point, back up the configuration first and then take action. This time I didn't reset it. I just cut off the power, restarted it, and changed the channel in the background to save it. In the future, if the 5G name suddenly disappears, I will first check the combined frequency and channel in the background, and then touch the power supply, which will save me a lot of detours.