My proposition - reset to default factory settings and then you can do new configuration.

Hi, Sorry for resurrecting the topic, but I have the same problem with my TL-WR340G-wireless is not visible in WiFi network.
Reset was not efficient, AC adapter changed also without effect.
I assume that the problem is in hardware-old condensers maybe. Opened, but not obvious leakage.
Does anybody experienced similar problems?

Reset was not efficient, AC adapter changed also without effect

Model of your wifi AC adapter?

with my TL-WR340G-wireless is not visible in WiFi network.

Have you changed wireless channel on the router?

jimasek wrote

Model of your wifi AC adapter?
Leader electronics Out: 9V-0.6A

Have you changed wireless channel on the router?

Several times, without success.

LEDs for SYS and Wireless are blinking, access to the router is possible via LAN cable, on witless statistics there is only sent packets, but 0 for received.

You tried on different wireless clients? Reset the router to facotry defaults and check if you can see its default Wi-Fi name.
If not, maybe it defective. By the way, this router is old. You may have to buy a new one.