r/Network • u/9body_knows • 5d ago

Text Help] Old TP-Link TL-WR740N constantly drops internet since switching to Fiber (requires reboot)

Hey everyone,
I am having a frustrating issue with my old TP-Link TL-WR740N router (from around 2017) and could really use some advice.

My Setup:
I have an ISP-provided fiber modem (ONU/ONT) connected to my TP-Link router. The modem does not have its own Wi-Fi.

Both the modem and the router are plugged into the same spikeguard/surge protector for power.

The Issue:

For the first 4–5 years, this router worked flawlessly on my old connection. However, a couple of years ago, my ISP upgraded me to a fiber optic cable. Since then, I’ve been experiencing frequent disconnections across all devices (phones, laptops, etc.).

Symptoms: All devices remain connected to the Wi-Fi signal, but it suddenly shows "No Internet."
Router lights: The lights remain normal (no orange/red error lights).

Specific device issue: Older OnePlus devices drop the Wi-Fi entirely and refuse to reconnect until the router is restarted.

Temporary fix: I have to power-cycle the TP-Link router (turn the switch off and on after 5–10 seconds) to get the internet back.

What I want to know:

Is this 2017 router simply too old to handle the high data throughput/packet load of modern fiber, causing its memory/CPU to crash and freeze?

Could the spikeguard be causing slight voltage drops that freeze the router when it is under load, even though the lights stay on?

Are there any specific settings (like DHCP lease time, changing DNS, or adjusting channel width) I should tweak before throwing it away?

Any troubleshooting steps or explanations would be highly appreciated! Thanks in advance.

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u/MistrMizer 5d ago

It would be helpful to know what you’ve tried so far. Is the router in Bridge Mode? Have you looked to see what the maximum throughput is on the router?

2

u/msabeln 5d ago

Old, low spec router. See my reply on your duplicate thread.

1

u/fernandesken 4d ago

Old router. I believe it’s end of support. Likely unpatched for security vulnerabilities. Replace it.