Does the printer keep showing offline after connecting to WiFi? If you change the router and it loses contact, it's almost certainly due to these three reasons

a little after nine in the evening, my wife threw me a review material and told me to print it out—the child needed it tomorrow. I clicked print, but the progress stripe didn't move at all, the printer icon was gray, and the status bar had two words: Offline. I've had an Epson L3158 at home for three years, but I use it less than ten times a year, and every time I need it, I just lose control. This time, I stayed alert and recorded the entire inspection process. I found that the printer going offline kept coming for three reasons, each less mysterious than the last.

take five minutes to clarify: is it a disconnect or a disconnection

this step is the easiest to skip and the easiest to skip. There are two completely different ways to go offline with a printer: one is that it is not connected to the internet itself, and the other is that it is hanging on the network and cannot be found on your computer. The direction of the repair is a hundred-eight thousand miles off.

first look at the light on the printer. A device without a screen like the L3158 relies entirely on its WiFi light: if the WiFi light stays on, it thinks it's networked; The WiFi light flashes slowly, indicating it is searching for the internet; The lights went out, but it just wasn't connected. Then open your phone, enter the router's backend, check the connected device list, and find a device with EPSON in its name—I always check this step first, much faster than messing around with drivers. How to read the router status page? I previously wrote an article interpreting the running status page, the device list is in the same backend.

My family was stuck in the first row that night. In the device list, EPSON is clearly online, with IP 192.168.31.66. My heart skipped a beat: Oh no, the port on my computer still points to the old address.

Culprit One: Moved IPs, Computers Still Point to Old Addresses

this is the largest proportion of offline faults, especially after changing routers. The principle is summarized in one sentence: When installing the printer driver, Windows pinned it to an IP address, which was written into the printer's TCP/IP port; Later, when the router was replaced or the DHCP lease expired and was reassigned, the printer's IP address changed, but the computer's port still kept pointing to the old address number. When knocked and no one answered, it would report offline.

This is my own. Originally, it was always at 192.168.31.108. Last month, the router lost power once. After restarting, DHCP redistributed the address pool, and the printer was pushed to 31.66. The computer didn't know, but kept knocking on the door of 108 over and over.

repair is simple. First, ping to confirm it's alive: press Win+R on the computer, type cmd and press Enter, and ping 192.168.31.66 it works, which means the machine is online. Then open Control Panel, Devices & Printers, right-click the printer, select Printer Properties, go to the "Ports" tab, select the original Standard TCP/IP Port, click "Configure Ports," change the IP address from 31.108 to 31.66, confirm, and then press a test page. On my side, it took less than three minutes.

the optical repair port is a temporary fix; next time the power goes out, it might still be moved. The root solution is simple: go to the router's backend and pin the printer to a single IP, use DHCP for static binding, fill in the MAC address, pick a corner in the address pool for it, and list which network devices in my home must be static. I've listed the printer first, just follow the instructions. See article on static IP binding. After tying this printer, I didn't disconnect for three years—until this time, because I was using an old router, the binding rules didn't follow after the switch.

By the way, I previously wrote about the process of replacing a new router. The core rule is to copy the WiFi name and password exactly from the old device, seamlessly switching all family devices. That article is here in . But the printer is the exception in that article: even if it connects to a new router itself, the computer port still has to be manually closed, which is harder to serve than the vacuum cleaner's camera.

Culprit 2: Printer network cards only recognize 2.4G, but dual-band integration causes confusion

Last month, my colleague

Lao Zhang bought a new HP DeskJet 2729 to do test papers for his child. The network setup took a whole night but didn't work out, so he asked me on WeChat. His symptoms are very typical: the phone has HP Smart installed, the app finds the printer, but the WiFi selection fails—either the WiFi name can't be found, or the connection disconnects within a second.

I asked him if his router has dual-band integration. He said yes, one name and two phones work fine. That's where the problem lies. On the market, whether Epson, HP, or Sibling, network cards are on the same level as vacuum cleaners and cameras, only recognizing 2.4G. A dual-band router will broadcast 2.4G and 5G under the same name. Smart devices like phones pick their own bands, but printers are stubborn—either they can't connect at all or the signal is terribly weak. I've written about this pitfall before in the vacuum cleaner network troubleshooting section, and the logic is exactly the same. That article is here in .

There are two

solutions. Convenient way: When configuring the router, temporarily separate the dual-band integration. 2.4G has its own name, let your phone connect to 2.4G, then install the printer, and after that, reconnect the dual-band system. Different companies have different names for router bands. I've compiled an article dual-band separation settings which you can copy. The solution is to leave the printer with a non-merged 2.4G name, since it doesn't need 5G speed anyway. The first route Old Zhang took was to split the bands and finish the dubbing in ten minutes, which made him so angry he said the whole night of fussing was wasted.

Culprit 3: Changed WiFi name or password, but had to manually reconfigure the network

my sister's family replaced the broadband router with a brand new router, the installer came up with a new WiFi name just to save the trouble. That day, all the family's phones and computers were connected, and everyone was happy. On the third day, they only realized the printer was missing when they needed to type something. This is the most straightforward type: the network name or password changes, the printer doesn't recognize the new network, and no one enters the new password for it, so it just can't get in.

re-reconfiguring a printer without a screen, there are only three options, and I've tried them all for my family:

First, WPS One-Click Configuration. Press and hold the router's WPS button for about two seconds, then press the network button on the printer. The printer's WiFi light will change from flashing to steady on. It's the fastest, but the premise is that your router's WPS is not turned off. For security reasons, many people turn this feature off. I once calculated the WPS principle after reading it. My approach is to turn it on temporarily, then turn it off after installation.

second, direct app connection and configuration. Install an Epson Printer Finder, follow the prompts to let the printer connect wirelessly, connect your phone to the temporary network starting with Direct, select your home WiFi in the app, enter the password, and you're done. HP corresponds to HP Smart—it's the same principle. This route doesn't require a router, which is suitable for my sister's type of router that can't reach in a weak current box.

third, the computer USB cable is included. Download the installer from the included CD or official website. Connect the printer to the computer with a USB cable. During driver installation, select wireless connection, and it will write the WiFi currently connected to your computer to the printer. The dumbest but most stable; use it to close when the first two fail.

one more reminder: changing WiFi names has a bigger ripple effect than expected. I once wrote an article about the rules for changing names after reconfiguring smart devices one by one. Taking a look before doing can save you a lot of trouble. The same goes for passwords—I've also explored three ways to change passwords, in .

three little-known facts I picked up on my way to repair a printer

First: The printer has its own webpage backend. Enter the browser's address bar directly into its IP, for example http://192.168.31.66, which can enter a simple but sufficient management page containing ink size, signal strength, and firmware version. When checking for signal issues, just one glance at the signal strength it reports is much more accurate than guessing. After setting up the site, add it to your browser bookmark. Next time offline, check if it's still there.

second: queue freezing is not a network issue. Once, the printer was short of paper and got stuck. After replenishing paper, it stopped typing, and even after deleting tasks, it couldn't delete and got stuck at 'Deleting.' This is a Windows printing backend service that is off-limits, unrelated to WiFi. Win+R enters services.msc and presses Enter, finds Print Spooler, right-clicks to stop, then goes to C:\Windows\System32\spool\PRINTERS directory to clear any remaining task files, then returns to start the service. The queue is instantly cleaned. I use this trick two or three times a year—it works every time.

Third: The less you use it, the more likely problems are to happen. If the printer goes unpowered for a long time, the network status in the cache is basically dead, and the router end has long since changed, so it doesn't know. My current habit is to plug it into the same power strip as the router. When the router is powered, it powers on, but don't let it cut power deeply for more than a week. Also, the idea of connecting a router via USB port to a printer is a different matter and doesn't conflict with the printer's built-in WiFi. If you want to know more, check out my previous post on printer connected to router .

take the right place and wrap up with a clear order

the sequence is five steps: check the lights, check the router device list, ping its IP, change the port or reconfigure the network, and bind the static IP to finish. That night, it took me less than half an hour from finding offline to typing out the review materials, with twenty minutes spent finding the new address 31.66. You don't need to worry about printers; their problems are much worse than routers. If you identify the three real culprits one by one, one will always match.