Many fiber internet problems come from dirty connectors or loose plugs, not major faults. Power cycling or restarting your ONT (Optical Network Terminal) often resolves simple troubleshooting internet issues. First, check the basics—look for power issues on your optical network terminal and inspect all cables for visible damage. But what do you do when fiber optic internet isn't available or practical due to location, infrastructure limitations, or common fiber internet issues?Although the FRITZ!Box is connected to a fiber optic connection (Fiber to the Home, FTTH) and configured to access the internet over fiber optics, some or all of the computers, smartphones, or other devices connected to the FRITZ!Box cannot access the internet.