Wireless router used for a long time the signal is not good for the following reasons:
Reason 1: This situation is related to the service life of the router!
Reason 2: The sensitivity of the wireless router's main control chip aging is bad, the replacement of the main control chip is good, but generally there is no such condition, the only way is to change the quality of the new brand router.
If it is really not assured, it is recommended to initialize the router and reset it once, so that there is no difference between it and the newly bought one, and the difference is the theoretical hardware life loss.