What do you do if your network is down and you need to diagnose and fix the issue in computer repair?

I agree with starting on the physical layer of the network connection. The modem and connection are essential to a properly operating setup.

In addition to steps already mentioned in this article, you can also: - Confirm if other devices on the network are also experiencing connectivity issues. This can help determine if the problem is isolated to one device or affects the entire network. - Use another device, such as a smartphone or laptop, to see if you can connect to the internet through the same network. This can help determine if the problem lies with endpoints or the network itself. - Sometimes, the issue may be with your computer rather than the network hardware. Restarting your computer can help refresh network settings and potentially resolve any software-related issues.

To troubleshoot network problems across Windows, Mac, and Linux operating systems, you can utilize built-in diagnostic tools tailored to each platform. In Windows, you can use tools like ipconfig, ping, tracert, netstat, Get-NetAdapter, and Get-NetConnectionProfile to diagnose most issues. On Linux, you have similar tools such as ifconfig, ping, traceroute, netstat, and dig. On Mac, you can use the Network Utility or Terminal to access commands. Many of the commands commonly used for network troubleshooting are similar or identical between macOS and Linux systems. If you need to delve deeper, utilize third-party tools like Wireshark, which offer advanced packet analysis capabilities for in-depth network troubleshooting.

Using a cable tester like the Fluke LinkIQ? Cable + Network Tester alongside visual inspection is a good strategy for addressing wired network issues. The LinkIQ? accurately measures cable lengths up to 1000 feet (305 m) and detects faults like opens, shorts, splits, NEXT failures and unterminated cables. It also conducts a comprehensive cable performance test, ensuring bandwidth from 10BASE-T to 10GBASE-T (10 Mb/s to 10 Gb/s). Moreover, it provides detailed switch information and conducts connectivity testing with IP ping, facilitating quick identification and resolution of network problems.

All good advice but it could be something as simple as an incorrect or corrupted device driver. Here are some other options: run Windows troubleshooter but, at times, it can't recognize the problem. Then, there's the loopback test with 127.0.01 to see if the computer is able to talk to itself. If not, go to Device Manager (DM) to see if there's a question mark or any type alert next to the communications device or, maybe a USB port, if it's a plug in device. If there's any type error in DM, a driver need to be found and installed. The computer manufacturer is a good starting point. If all is good in DM and the device is properly powered, I would go onto the recommended steps!