Five quick steps: (1) reboot your modem/router (unplug 30 seconds); (2) run a speed test over Ethernet, not WiFi, to isolate the wireless variable; (3) compare the result to your actual plan speed; (4) check your modem's status lights — a red or flashing connection light usually means a line fault; (5) if it's only slow during 7–10pm, that's often ISP peak-hour congestion rather than a fault in your home. If none of that resolves it, we can usually pinpoint the cause within an hour on-site.

五个快速自查步骤：①重启光猫/路由器(断电30秒再开)；②用网线而不是WiFi测速，排除无线因素；③对比实测结果和你实际购买的套餐速度；④查看光猫指示灯，红灯或闪烁通常代表线路故障；⑤如果只是晚上7-10点变慢，多半是ISP晚高峰拥堵，不是家里的问题。这些都排除不了的话，我们上门通常一小时内能定位原因。