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Wi-Fi Keeps Disconnecting? 5 Causes, Sorted by Symptom

Note: This article was automatically translated from Korean by AI. See Korean original for the most accurate reading.

Bottom line — Wi-Fi dropping out doesn’t have just one cause.
Whether it’s everyone or just one device and whether it’s regular or irregular
answering just these two questions narrows the cause down to one of five branches.
If you just reboot the router and call it done, the same thing repeats a few days later.

First check these two things. Where you should look next depends entirely on the answer.

  • Does every device in the house drop at the same time, or just one device?
  • Does it drop at regular intervals, or irregularly?

① All Devices, Regular Intervals → DHCP Lease Time

A router assigns IP addresses to devices on a lease basis, and how long that lease lasts is called the DHCP lease time (see RFC 2131, the DHCP standard).
If this value is set too short, reassignment happens every time it expires, and the connection drops and reconnects at that exact moment.

If the interval is regular — like clockwork every 3 minutes — this should be your first suspect.
Check the lease time in your router’s DHCP settings, and if it’s set short, extend it (typically to 12 hours–1 day).

② All Devices, Irregular → Channel Interference or Router Overheating

In densely packed housing where many routers are nearby, interference occurs with neighboring signals on the same channel.
Switching your router’s channel setting from automatic to manual and locking it to a less congested channel sometimes helps.

If it gets noticeably worse in summer, overheating is also worth suspecting. Don’t place your router in an enclosed space or on top of another device.
If it feels hot to the touch, simply moving it somewhere with better ventilation can make a difference.

③ Only One Device Drops (Others Are Fine) → That Device’s Power Management

If “the computer is fine but only the phone drops,” or vice versa, it’s not a router problem.
It’s common for that device’s power-saving feature to be shutting off its wireless adapter.

  • Windows — Device Manager → Network adapters → Wireless adapter properties → Power Management →
    uncheck “Allow the computer to turn off this device to save power”
  • Android — Exclude wireless-related items from battery optimization / power-saving mode

If you don’t check this and keep fiddling only with the router, it won’t get fixed.

④ Only 5GHz Fails to Connect → Band Issue

If your router broadcasts 2.4GHz and 5GHz under the same network name (band steering), devices switching between them can look like they’re dropping.
Also, 5GHz is faster but doesn’t penetrate walls as well. This is often the reason it drops when you move to another room.

To diagnose this, split the two bands into separate network names and connect to each individually.
If 2.4GHz works fine but only 5GHz fails, distance or obstacles are the likely cause.

⑤ You’ve Checked All Four Above and It’s Still Happening → the Line or the Router Itself

The problem may not be the router but the internet line itself.
Connect your PC directly to the modem, bypassing the router, and check whether it still drops — this will tell them apart.

If it still drops on a direct connection, it’s a line issue and you’ll need to contact your internet provider.

If the direct connection is fine but it drops once the router is in the loop, the router is the problem.
Try updating the firmware to the latest version, and if it keeps happening, it may be time to consider a replacement.

In Order

Symptom Prime Suspect How to Check
All devices · regular interval DHCP lease time Router’s DHCP settings
All devices · irregular Channel interference / overheating Manually lock the channel, check router placement
Only one device That device’s power management Disable power-saving settings
Only 5GHz Band / distance Separate the band names and test each
None of the above apply The line or the router Direct-to-modem test

FAQ

Q1. Rebooting the router fixes it briefly, so why does it drop again?

A reboot only clears the symptom temporarily — it doesn’t remove the cause.
If the actual cause is the DHCP lease time or channel interference, the same conditions recur once enough time has passed.
Keeping track of how long after a reboot it drops again will help you narrow down which of the five branches applies.

Q2. My internet speed tests fine, but it keeps dropping.

Speed and connection stability are different problems. Speed is about bandwidth; dropping is about maintaining the connection.
Don’t assume that because your speed test looks good, that rules out the connection issue.

Q3. Would buying a new router fix this?

If the cause is ③ (device power management) or ⑤ (the line), a new router won’t change anything.
Before buying one, run the direct-to-modem test first to rule the line in or out.

Q4. My Wi-Fi icon shows an exclamation mark.

This means you’re connected to the router but not reaching the internet.
It’s a sign to look outside the router rather than between the router and your device, so it’s faster to start checking from ⑤.


※ Menu names in router admin screens vary by manufacturer and model. Standard information on bands and specifications is available from the Wi-Fi Alliance.
This article is based on general operating principles such as DHCP, band behavior, and power management.
Hardware failure in a specific device can’t be verified remotely, so if none of the five branches above narrow things down,
contact your device manufacturer’s or internet provider’s technical support.

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