Troubleshoot Your Network Like a Boss

For years, most of the service calls my company received were cable TV-related. And it didn’t matter if the customer’s TV screen read “No Signal,” there was no sound, image quality was poor, or they couldn’t change channels or access the program guide, all issues were usually fixed with one simple action: rebooting the cable box.

Nowadays, the service calls we get usually involve issues with a home’s network.

“My Wi-Fi is slow.” “I can’t connect to the internet.” And the biggie: “I can’t get Netflix to play.” (“I can’t get Disney+ to play” is also starting to climb the service call charts.)

Unfortunately, troubleshooting a network issue is not always as simple and straightforward as rebooting a cable box. And trying to diagnose the problem can lead you deep down a troubleshooting rabbit hole. Fortunately, I’ve spent hours in that hole, and can offer tips that should help get you back to that marathon Bridgerton streaming session ASAP.

How Big Is the Problem?
The first step in figuring out what’s wrong is to figure out exactly what is wrong. Is the entire network down all over the house? Is it limited to just devices connected via Wi-Fi or does it affect hardwired devices too? Is it every device, ones in certain areas, or just a specific unit? Is the network not working at all, or is it an issue with a specific app or service like Netflix? Finding the answers to these questions will tell you where to begin.

My Entire Network Is Down!
If the network is down — meaning no devices in the home have network/internet connectivity — the problem likely lies with the cable or DSL modem, which is usually provided by your Internet Service Provider (ISP), or the router. Depending on the size of your home’s network, these two might be combined into a single unit. A modem typically has three connections: power, network out (an RJ45 Ethernet jack), and signal in (typically an RG6 coax cable, same as a cable TV connection). On the front are usually four lights indicating power, download, upload, and network connectivity. A router will provide more connections, but the three key ones are: power, WAN (Wide Area Network — data incoming from the modem), and LAN (Local Area Network — data out to your devices).

(Note: Some ISPs install the modem outside your home where you won’t necessarily have access to it — a common scenario when fiber is used to carry the signal. If this case applies to you, skip over to the next part.)

To restore network connectivity, you’ll want to start by unplugging both the modem and router from power. Wait a few minutes, and then power on the modem only. Modems usually have four lights to indicate power, download, upload, and internet connectivity. Wait until these lights settle into a normal rhythm or remain solid, and then power up the router. Give it a few more moments and check the network connection on one of your devices. If it’s working, yay, you did it! If not…

Test Directly at Modem
Because the modem sits at the top of your home’s internet delivery pyramid, you’ll want to confirm it has an incoming signal before proceeding. If you notice something obvious like, “Hey, you said there are supposed to be four lights on my modem, and I have none,” then skip right to the part where you call your ISP for help, because you’re likely dealing with either a dead modem or an internet outage in your area, neither of which you’ll be able to fix.

Assuming neither of the above apply, you’re going to want to power cycle the modem again. But this time, disconnect the Ethernet cable linking the modem with your router’s WAN input before powering it on. (You can’t do this if you have a modem/router combo, so instead disconnect all the other Ethernet cables from the LAN outputs.) When the modem comes back online, connect a computer directly to the modem’s Ethernet output. Obviously, this will require a computer with an Ethernet port, a feature that’s sadly starting to disappear from new PCs and Macs, though adapters are available. Once you’ve made the connection directly to the modem, test once again for network connectivity. If it works, great, we can now move on. If not, we’re dealing with either a dead modem or an internet outage and you’ll need to call your ISP. Sorry!

Test at Router
Assuming we had success with making a connection directly to the modem, we can now move on to testing the connection directly at the router. We start by — you guessed it — power cycling the modem, the router, and the computer you had used for testing. But before powering the router back on, reconnect the WAN connection to the modem and then disconnect everything else from the router.

When things are fully powered back on, connect your device to one of the router’s LAN ports. If you don’t have a connection, a bad router is the likely culprit. If you do have one — great! Reconnect any devices linked to the router’s LAN ports and test for network connectivity around the house. Are some of your devices still not working? Don't worry — that’s something we’ll cover in part 2 of this blog!

The Author
For the past 20 years, John Sciacca has worked as a custom installer in South Carolina. In his free time, he enjoys drinking craft beer and watching movies on his 7.2.6 surround system.

jeff-henning's picture

Without getting into minutia, this kind of stuff is the most frustrating to fix.

Displacing & replacing cables as well as breaking your system down to its most basic config is a gigantic pain in the ass, but the only way to find out what has gone wrong when the quick fix doesn't work.

I have a 7 year old Samsung TV that, last year, started glitching all the time using WiFi for Netflix streaming. I then bought CAT8 cabling from Monoprice and the glitching abated somewhat, but wasn't fixed.

Doing some research, I suspected that the problem was the TV since everything else was primo.

Upon forgoing the TV's streamer and buying a Nvidia Shield Pro, every problem was cleared up. The TV's CPU just could no longer decode HEVC content well anymore. It was running out of bandwidth.

While this was rather straight forward, it always sucks to have to tear your system apart and find out that it's a cable that worked perfectly for 8 years. There's several hours you aren't getting back.