How to self-check WiFi signal blind spots at home? Don't rush to buy Mesh; just walk around with your phone and the culprit will be revealed

the master bedroom, I've been watching videos for half a year. My wife finally couldn't take it anymore: Let's get a new router. The one online selling for just over 400 yuan looks impressive. I said, don't rush to pay for this money yet. If the signal is bad, you need to figure out whether the machine is bad or if the signal simply doesn't work. Last Sunday afternoon, I spent over half an hour drawing a floor plan and walking through all five houses with my phone in hand. The answer came immediately: it's not an aging router, but a load-bearing wall and a refrigerator that are eating up the signal tightly. This article will cover this old method from scratch. If you follow it for a while, you might even save a lot of unnecessary money.

Step 1 is to clarify: are there still people causing trouble in the real blind spot

poor signal actually falls into two types of problems, with completely opposite approaches to treatment. Treating them together is essentially a wasted effort.

first is called "always poor." When you enter the master bedroom, only two bars of signal remain. Day and night are the same, and you can't get back from any corner of the room—this is a real blind spot, the signal is physically blocked. This article mainly addresses it.

second is called 'sometimes good, sometimes bad.' At the same spot, sometimes it runs smoothly; as soon as it's mealtime or around seven or eight in the evening, they start spinning around. This is probably not a wall issue, but interference: once the microwave is turned on, the neighbor's router channels are crowded, and the Bluetooth devices multiply, the signal gets scattered. There are ways to check for interference: use an app to check the usage of nearby channels, and switch to a quieter channel, which can greatly improve things. I wrote about this in the of the channel interference section, so I won't elaborate on it here.

method is clumsy but accurate: test the same point once in the morning, noon, and evening. If all three times are different, that's a true blind spot; if the result is inconsistent, it's interference. My kitchen is the most insidious, a case of two problems combined—the baseline is already poor, and as soon as the microwave heats up food, it drops from 'barely usable' out of the service area. So don't restart your router as soon as it gets stuck; first figure out what kind of illness you have.

Step

two: draw a floor plan and take a walk around with your phone

find a piece of paper to draw the layout. You don't need to be precise—just the room frame and the position of the door. Then I took my phone and walked through each house, recording two numbers: signal strength dBm and how many megameters the speed test could run at that time. Which station to use for speed measurement and how to test without falsification? Check the speed measurement posture I wrote before; here I will only talk about signals.

don't judge the signal by the bars—the bars are deceiving—refresh is a beat slow. When the dual-band is combined, the phone often displays 2.4G bars, and the four-bar scale is too thick—-60 and -75 might both show two bars. Check the dBm (dBm) as a negative value: Android phones can check WiFi details or WiFiAnalyzer apps; iPhones can install an AirPort utility tool and enable Wi-Fi scanning; if you have Xiaomi devices at home, the WiFi Treasure Box in the Mijia app is the most convenient.

How to read

numbers? Just remember three levels: use anything under -50, and it's stable for 4K gaming; -60 to -70 is usable, video is passable, but games will float; Once it's over -70, don't fantasize about your speed; anything above -80 is basically no internet. I assign colors to each unit: green, yellow, and red. After drawing the floor plan, you can immediately tell which part is "dark under the lights."

leave, stand in a representative position: by the bed, sofa, by the toilet, in front of the stove. Wherever you are, just stand and check your phone—don't stand in the center of the room feeling moved. If you're patient, run through 2.4G and 5G each once—the attenuation between the two bands is different, and this difference will be very useful later.

Step 3: Identify the culprit at the location—these are probably the five main points

mark the red and yellow zones, return to the floor plan and connect the straight lines: from the router to the missing point, what does this line pass through? I looked at my home map for a long time and flipped through a lot of attenuation data. The main culprits for signal blocking at home are basically these five, ranked from mild to heavy.

here's a physics note: for every 3 dB difference in dBm, the signal power is cut in half. What does it mean for a load-bearing wall to absorb 20dB? The signal was only one percent of the original when it passed through. So "the router is clearly right next door but can't be found" really isn't because the machine is bad, but because the wall has both reinforced mesh and moisture. 2.4G hits a wall and gets a layer of skin, and 5G is even worse—the higher the frequency, the more you fear the walls, and using the same 5G route means losing several dB more. That's why 5G is lightning fast in the living room, but once you step into the master bedroom, it's actually less than 2.4G.

metal blocking is even more extreme—not absorption, but reflection, essentially blocking the signal. At the spot in my kitchen, a double-door refrigerator stands right in the middle of the line from the living room. The numbers look bad, but it's thanks to the credit for that. The aquarium may look harmless, but 2.45GHz is actually the frequency range where water molecules absorb energy—microwaves heat food on this, and your 1.2-meter-tall fish tank is basically a small "signal microwave."

my home survey: one wall plus one refrigerator

here are the actual measurements of five points at my home. You can compare them and feel that "what's between us" is much more important than "how far apart" is.

pattern is clear: as long as there are load-bearing walls or major appliances along the path, 5G is basically useless, while 2.4G can still hold out; The two worst spots in the whole house are the master bedroom behind load-bearing walls, and the kitchen blocked by a refrigerator—both have nothing to do with the router brand. I said this with confidence, because later a friend sent me a top-tier flagship phone for me to test and play. Placed in the same spot, passing through this load-bearing wall dropped 20dB or 20dB, and the master bedroom numbers barely changed. No matter how powerful the hardware, physical hardware doesn't lose value.

three tricks for zero money, save one and then

confirmed the culprit, he first tried out the free trick.

first trick: move the router. The signal was sent evenly in all directions; the machine was stuffed into a weak current box or hidden in the metal compartment of the TV cabinet, which was like cutting yourself twice before going out. Bring it out and raise it to the top of the cabinet about 1.5 meters, with the antenna standing upright, and the overall area slightly offset toward the main activity area. Pay special attention not to place it against load-bearing walls: placing it against the wall makes the room behind the wall even more hopeless; Moving half a meter toward the open area can move most families back to the yellow zone with just this step. I used five moving tests to write an article where to place the router, so I won't repeat it here.

second move: the Communication Dao. If neighboring routers squeeze into the same channel, it's like the whole class is competing to speak at the same time—no one can hear clearly. Check the mobile app and see the usage of the peripherals; switch to the most convenient 2.4G option among 1, 6, and 11. This trick mainly treats 'sometimes good, sometimes bad' and has limited help for the true blind spot, but its advantage is zero cost, so you can set it up effortlessly.

third trick: connect devices to the right frequency bands. The phone and computer in the blind spot manually pin down 2.4G, so don't let it cling to the false 5G signal—when the dual-band is combined, the phone guesses the frequency band by itself; if it guesses wrong, it gets stuck on the two bars of signal and spins. As for smart devices like vacuum cleaners and cameras that only recognize 2.4G, they need to be placed closer to the router. Network failures and frequent disconnections are mostly due to insufficient signal feed. I blow up five times to figure out the .

how to spend money when it's time to spend it, and the untreated blind spots

zero-cost tricks are still short of a breath, then consider spending money. Spending comes in three tiers, moving from cheap to expensive.

first tier, zero to fifty yuan, old routes are reused as waste. I my old discarded machine at home using the AP wiring method, and placed it between the blind spot and the router for relay. The downside is that the speed is cut in half, and the replacement process is seamless, but the advantage is that it's cheap and satisfying. Second tier: 100 to 300 km/h, mesh 1 to 1 to 1. This is the mainstream answer to the current blind spot problem: wireless backhaul is convenient, and wired backhaul is more stable with embedded network cables. Where to place the sub-router is important: place it at the "middle blind spot" between the router and the blind spot, don't just stuff it into the blind spot. I've written about the specific method the clumsy method of measuring eight points while holding your phone, just copy it. Third, if the renovation includes pre-installed network cables, directly install the panel AP. This AC is the most thorough AP and the highest cost. Whether it's worth it depends on the condition of the house and your budget.

pouring cold water on the matter: so-called signal amplifiers online costing tens or hundreds of yuan are essentially first-tier repeaters, and they're relays with speed cut in half. Most of the time, they're not as cost-effective as old routers that gather dust at home. Think carefully before ordering—I've tested it once , and here's one conclusion.

there's another situation that really doesn't need treatment: storage rooms, balcony corners, hallways—these places you barely use your phone a few times a year. If they're red, so be it—spending money on them is the real waste. There are only two things worth worrying about—the bedside of the bedroom where you spend a lot of time scrolling on your phone, and the corner where smart devices are clustered. Disconnecting devices is much more annoying than losing the internet. Diagnose first, then spend money—don't go back in this order.